diff --git a/app/src/app/components/sidebar/BrushSizeSelector.tsx b/app/src/app/components/sidebar/BrushSizeSelector.tsx
index 69d85bd8..e6efa0eb 100644
--- a/app/src/app/components/sidebar/BrushSizeSelector.tsx
+++ b/app/src/app/components/sidebar/BrushSizeSelector.tsx
@@ -1,6 +1,15 @@
-import { Slider, Flex } from "@radix-ui/themes";
+import { Slider, Flex, Heading, Text } from "@radix-ui/themes";
 import { useMapStore } from "../../store/mapStore";
 
+/**
+ * BrushSizeSelector
+ * Note: right now the brush size is an arbitrary value between
+ * 1 and 100. This is slightly arbitrary. Should we communicate brush size
+ * differently or not display the brush size?
+ *
+ * @description A slider to select the brush size
+ * @returns {JSX.Element} The component
+ */
 export function BrushSizeSelector() {
   const brushSize = useMapStore((state) => state.brushSize);
   const setBrushSize = useMapStore((state) => state.setBrushSize);
@@ -11,8 +20,15 @@ export function BrushSizeSelector() {
   };
 
   return (
-    <Flex direction="row" gap="4" maxWidth="300px" style={{alignItems:'center'}}>
-        <h4>Brush Size</h4>
+    <Flex direction="row" gap="4" maxWidth="300px" mb="3" align="center">
+      <Heading
+        as="h4"
+        size="2"
+        weight="regular"
+        style={{ whiteSpace: "nowrap" }}
+      >
+        Brush Size
+      </Heading>
       <Slider
         defaultValue={[brushSize]}
         size="2"
@@ -20,7 +36,9 @@ export function BrushSizeSelector() {
         min={1}
         max={100}
       />
-      {brushSize}
+      <Text size="2" as="span" color="gray">
+        {brushSize}
+      </Text>
     </Flex>
   );
 }
diff --git a/app/src/app/components/sidebar/ColorPicker.jsx b/app/src/app/components/sidebar/ColorPicker.jsx
index 25f7de1f..ba3ef7c8 100644
--- a/app/src/app/components/sidebar/ColorPicker.jsx
+++ b/app/src/app/components/sidebar/ColorPicker.jsx
@@ -1,5 +1,5 @@
 import React, { useState } from "react";
-import { palette, color10 } from "../../constants/colors";
+import { _colorScheme, colorScheme } from "../../constants/colors";
 import { Button } from "@radix-ui/themes";
 import { styled } from "@stitches/react";
 import * as RadioGroup from "@radix-ui/react-radio-group";
@@ -7,15 +7,13 @@ import { blackA } from "@radix-ui/colors";
 import { useMapStore } from "../../store/mapStore";
 
 export function ColorPicker() {
-  const [color, setColor] = useState(null);
-  const [open, setOpen] = useState(false);
   const selectedZone = useMapStore((state) => state.selectedZone);
   const setSelectedZone = useMapStore((state) => state.setSelectedZone);
   const setZoneAssignments = useMapStore((state) => state.setZoneAssignments);
   const accumulatedGeoids = useMapStore((state) => state.accumulatedGeoids);
   const resetAccumulatedBlockPopulations = useMapStore((state) => state.resetAccumulatedBlockPopulations);
   
-  const colorArray = color10;
+  const colorArray = colorScheme;
   if (!colorArray) return null;
   const handleRadioChange = (value) => {
     console.log(
diff --git a/app/src/app/components/sidebar/MapModeSelector.jsx b/app/src/app/components/sidebar/MapModeSelector.jsx
index 6bee337d..5d6ff113 100644
--- a/app/src/app/components/sidebar/MapModeSelector.jsx
+++ b/app/src/app/components/sidebar/MapModeSelector.jsx
@@ -15,7 +15,7 @@ export function MapModeSelector() {
   const activeTools = [
     { mode: "pan", disabled: false, label: "Pan", icon: <HandIcon /> },
     { mode: "brush", disabled: false, label: "Brush", icon: <Pencil2Icon /> },
-    { mode: "erase", disabled: true, label: "Erase", icon: <EraserIcon /> },
+    { mode: "eraser", disabled: false, label: "Erase", icon: <EraserIcon /> },
   ];
 
   const handleRadioChange = (value) => {
diff --git a/app/src/app/components/sidebar/Sidebar.tsx b/app/src/app/components/sidebar/Sidebar.tsx
index e793a7c2..1c1aed30 100644
--- a/app/src/app/components/sidebar/Sidebar.tsx
+++ b/app/src/app/components/sidebar/Sidebar.tsx
@@ -24,13 +24,17 @@ export default function SidebarComponent() {
         </Heading>
         <GerryDBViewSelector />
         <MapModeSelector />
-        {activeTool === "brush" ? (
+        {activeTool === "brush" || activeTool === "eraser" ? (
           <div>
-            <ColorPicker />
             <BrushSizeSelector />
             <PaintByCounty />{" "}
           </div>
         ) : null}
+        {activeTool === "brush" ? (
+          <div>
+            <ColorPicker />
+          </div>
+        ) : null}
         <ResetMapButton />
         <Tabs.Root defaultValue="layers">
           <Tabs.List>
diff --git a/app/src/app/components/sidebar/charts/HorizontalBarChart.tsx b/app/src/app/components/sidebar/charts/HorizontalBarChart.tsx
index 0190b950..8c4d609b 100644
--- a/app/src/app/components/sidebar/charts/HorizontalBarChart.tsx
+++ b/app/src/app/components/sidebar/charts/HorizontalBarChart.tsx
@@ -9,7 +9,7 @@ import {
   YAxis,
   Cell,
 } from "recharts";
-import { color10 } from "@/app/constants/colors";
+import { colorScheme } from "@/app/constants/colors";
 
 type TooltipInput = {
   active?: boolean;
@@ -56,7 +56,8 @@ export const HorizontalBar = () => {
       </Heading>
       <ResponsiveContainer
         width="100%"
-        height={color10.length * 18}
+        // should this instead be set based on the target number of zones? see https://github.com/districtr/districtr-v2/issues/92
+        height={colorScheme.length * 18}
         minHeight="200px"
       >
         <BarChart
@@ -78,7 +79,10 @@ export const HorizontalBar = () => {
             {mapMetrics.data
               .sort((a, b) => a.zone - b.zone)
               .map((entry, index) => (
-                <Cell key={`cell-${index}`} fill={color10[entry.zone - 1]} />
+                <Cell
+                  key={`cell-${index}`}
+                  fill={colorScheme[entry.zone - 1]}
+                />
               ))}
           </Bar>
         </BarChart>
diff --git a/app/src/app/constants/colors.ts b/app/src/app/constants/colors.ts
index 5c74147b..d4249155 100644
--- a/app/src/app/constants/colors.ts
+++ b/app/src/app/constants/colors.ts
@@ -27,63 +27,47 @@ import {
   sky,
 } from "@radix-ui/colors";
 
-export const palette = {
-  colors: {
-    ...(tomato as object),
-    ...(red as object),
-    ...(ruby as object),
-    ...(crimson as object),
-    ...(pink as object),
-    ...(plum as object),
-    ...(purple as object),
-    ...(violet as object),
-    ...(iris as object),
-    ...(indigo as object),
-    ...(blue as object),
-    ...(cyan as object),
-    ...(teal as object),
-    ...(jade as object),
-    ...(green as object),
-    ...(grass as object),
-    ...(orange as object),
-    ...(amber as object),
-    ...(yellow as object),
-    ...(gold as object),
-    ...(brown as object),
-    ...(bronze as object),
-    ...(gray as object),
-    ...(mint as object),
-    ...(lime as object),
-    ...(sky as object),
-  } as { [key: string]: { [key: string]: string } },
-};
-
-// bright colors!
-export const color10 = [
-  tomato.tomato10,
-  red.red10,
-  ruby.ruby10,
-  crimson.crimson10,
-  pink.pink10,
-  plum.plum10,
-  purple.purple10,
-  violet.violet10,
-  iris.iris10,
-  indigo.indigo10,
-  blue.blue10,
-  cyan.cyan10,
-  teal.teal10,
-  jade.jade10,
-  green.green10,
-  grass.grass10,
-  orange.orange10,
-  amber.amber10,
-  yellow.yellow10,
-  gold.gold10,
-  brown.brown10,
-  bronze.bronze10,
-  gray.gray10,
-  mint.mint10,
-  lime.lime10,
-  sky.sky10,
+export const colorScheme = [
+  "#0099cd",
+  "#ffca5d",
+  "#00cd99",
+  "#99cd00",
+  "#cd0099",
+  "#aa44ef", // lighter, req from San Diego
+  // Color brewer:
+  "#8dd3c7",
+  "#bebada",
+  "#fb8072",
+  "#80b1d3",
+  "#fdb462",
+  "#b3de69",
+  "#fccde5",
+  "#bc80bd",
+  "#ccebc5",
+  "#ffed6f",
+  "#ffffb3",
+  // other color brewer scheme:
+  "#a6cee3",
+  "#1f78b4",
+  "#b2df8a",
+  "#33a02c",
+  "#fb9a99",
+  "#e31a1c",
+  "#fdbf6f",
+  "#ff7f00",
+  "#cab2d6",
+  "#6a3d9a",
+  "#b15928",
+  // random material design colors:
+  "#64ffda",
+  "#00B8D4",
+  "#A1887F",
+  "#76FF03",
+  "#DCE775",
+  "#B388FF",
+  "#FF80AB",
+  "#D81B60",
+  "#26A69A",
+  "#FFEA00",
+  "#6200EA",
 ];
diff --git a/app/src/app/constants/layers.ts b/app/src/app/constants/layers.ts
index 314c2917..508a3a9f 100644
--- a/app/src/app/constants/layers.ts
+++ b/app/src/app/constants/layers.ts
@@ -7,8 +7,8 @@ import { MutableRefObject } from "react";
 import { Map } from "maplibre-gl";
 import { getBlocksSource } from "./sources";
 import { DocumentObject } from "../utils/api/apiHandlers";
-import { color10 } from "./colors";
 import { MapStore, useMapStore } from "../store/mapStore";
+import { colorScheme } from "./colors";
 
 export const BLOCK_SOURCE_ID = "blocks";
 export const BLOCK_LAYER_ID = "blocks";
@@ -46,10 +46,14 @@ export const COUNTY_LAYER_IDS: string[] = [
 export const LABELS_BREAK_LAYER_ID = "places_subplace";
 
 const colorStyleBaseline: any[] = ["case"];
-export const ZONE_ASSIGNMENT_STYLE_DYNAMIC = color10.reduce((val, color, i) => {
-  val.push(["==", ["feature-state", "zone"], i + 1], color); // 1-indexed per mapStore.ts
-  return val;
-}, colorStyleBaseline);
+
+export const ZONE_ASSIGNMENT_STYLE_DYNAMIC = colorScheme.reduce(
+  (val, color, i) => {
+    val.push(["==", ["feature-state", "zone"], i + 1], color); // 1-indexed per mapStore.ts
+    return val;
+  },
+  colorStyleBaseline
+);
 ZONE_ASSIGNMENT_STYLE_DYNAMIC.push("#cecece");
 
 // cast the above as an ExpressionSpecification
diff --git a/app/src/app/constants/types.ts b/app/src/app/constants/types.ts
index 99c8330b..c1b70628 100644
--- a/app/src/app/constants/types.ts
+++ b/app/src/app/constants/types.ts
@@ -1,6 +1,6 @@
 import type { MapOptions, MapLibreEvent } from "maplibre-gl";
 
-export type Zone = number;
+export type Zone = number | null;
 
 export type GEOID = string;
 
diff --git a/app/src/app/store/mapStore.ts b/app/src/app/store/mapStore.ts
index 2eacd4f6..b8863852 100644
--- a/app/src/app/store/mapStore.ts
+++ b/app/src/app/store/mapStore.ts
@@ -63,9 +63,7 @@ export interface MapStore {
   setSelectedZone: (zone: Zone) => void;
   accumulatedBlockPopulations: Map<string, number>;
   resetAccumulatedBlockPopulations: () => void;
-  // TODO: Add parent/child status to zoneAssignments
-  // Probably, something like Map<string, { zone: number, child?: boolean }>
-  zoneAssignments: Map<string, number>; // geoid -> zone
+  zoneAssignments: Map<string, Zone>; // geoid -> zone
   setZoneAssignments: (zone: Zone, gdbPaths: Set<GDBPath>) => void;
   loadZoneAssignments: (assigments: Assignment[]) => void;
   resetZoneAssignments: () => void;
diff --git a/app/src/app/utils/events/handlers.ts b/app/src/app/utils/events/handlers.ts
index e234521e..af967610 100644
--- a/app/src/app/utils/events/handlers.ts
+++ b/app/src/app/utils/events/handlers.ts
@@ -2,6 +2,7 @@ import { BLOCK_SOURCE_ID } from "@/app/constants/layers";
 import { MutableRefObject } from "react";
 import { Map, MapGeoJSONFeature } from "maplibre-gl";
 import { debounce } from "lodash";
+import { Zone } from "@/app/constants/types";
 import { MapStore } from "@/app/store/mapStore";
 
 /**
@@ -11,7 +12,7 @@ import { MapStore } from "@/app/store/mapStore";
  * @returns void - but updates the zoneAssignments and zonePopulations in the store
  */
 const debouncedSetZoneAssignments = debounce(
-  (mapStoreRef: MapStore, selectedZone: number, geoids: Set<string>) => {
+  (mapStoreRef: MapStore, selectedZone: Zone, geoids: Set<string>) => {
     mapStoreRef.setZoneAssignments(selectedZone, geoids);
 
     const accumulatedBlockPopulations = mapStoreRef.accumulatedBlockPopulations;
@@ -41,6 +42,16 @@ export const SelectMapFeatures = (
   map: MutableRefObject<Map | null>,
   mapStoreRef: MapStore,
 ) => {
+  let {
+    accumulatedGeoids,
+    accumulatedBlockPopulations,
+    activeTool,
+    selectedZone,
+  } = mapStoreRef;
+  if (activeTool === "eraser") {
+    selectedZone = null;
+  }
+
   features?.forEach((feature) => {
     map.current?.setFeatureState(
       {
@@ -48,14 +59,14 @@ export const SelectMapFeatures = (
         id: feature?.id ?? undefined,
         sourceLayer: feature.sourceLayer,
       },
-      { selected: true, zone: mapStoreRef.selectedZone },
+      { selected: true, zone: selectedZone },
     );
   });
   if (features?.length) {
     features.forEach((feature) => {
-      mapStoreRef.accumulatedGeoids.add(feature.properties?.path);
+      accumulatedGeoids.add(feature.properties?.path);
 
-      mapStoreRef.accumulatedBlockPopulations.set(
+      accumulatedBlockPopulations.set(
         feature.properties?.path,
         feature.properties?.total_pop,
       );
@@ -80,7 +91,7 @@ export const SelectZoneAssignmentFeatures = (mapStoreRef: MapStore) => {
   if (accumulatedGeoids?.size) {
     debouncedSetZoneAssignments(
       mapStoreRef,
-      mapStoreRef.selectedZone,
+      mapStoreRef.activeTool === "brush" ? mapStoreRef.selectedZone : null,
       mapStoreRef.accumulatedGeoids,
     );
   }
diff --git a/app/src/app/utils/events/mapEvents.ts b/app/src/app/utils/events/mapEvents.ts
index 5755d12c..48dd2793 100644
--- a/app/src/app/utils/events/mapEvents.ts
+++ b/app/src/app/utils/events/mapEvents.ts
@@ -33,14 +33,11 @@ export const handleMapClick = (
   if (activeTool === "brush" || activeTool === "eraser") {
     const selectedFeatures = mapStore.paintFunction(map, e, mapStore.brushSize);
 
-    if (activeTool === "brush" && sourceLayer) {
+    if (sourceLayer) {
       // select on both the map object and the store
       SelectMapFeatures(selectedFeatures, map, mapStore).then(() => {
         SelectZoneAssignmentFeatures(mapStore);
       });
-    } else if (activeTool === "eraser") {
-      // erase features
-      // TODO: implement eraser
     }
   } else {
     // tbd, for pan mode - is there an info mode on click?
@@ -55,7 +52,7 @@ export const handleMapMouseUp = (
   const activeTool = mapStore.activeTool;
   const isPainting = mapStore.isPainting;
 
-  if (activeTool === "brush" && isPainting) {
+  if ((activeTool === "brush" || activeTool === "eraser") && isPainting) {
     // set isPainting to false
     mapStore.setIsPainting(false);
     SelectZoneAssignmentFeatures(mapStore);
@@ -75,12 +72,7 @@ export const handleMapMouseDown = (
   } else if (activeTool === "brush" || activeTool === "eraser") {
     // disable drag pan
     map.current?.dragPan.disable();
-    if (activeTool === "brush") {
-      mapStore.setIsPainting(true);
-      return;
-    } else if (activeTool === "eraser") {
-      // erase features tbd
-    }
+    mapStore.setIsPainting(true);
   }
 };
 
diff --git a/backend/app/alembic/versions/09d011c1b387_zones_can_be_null.py b/backend/app/alembic/versions/09d011c1b387_zones_can_be_null.py
index a1f15eb6..d795225b 100644
--- a/backend/app/alembic/versions/09d011c1b387_zones_can_be_null.py
+++ b/backend/app/alembic/versions/09d011c1b387_zones_can_be_null.py
@@ -5,7 +5,6 @@
 Create Date: 2024-09-09 13:34:59.347083
 
 """
-
 from typing import Sequence, Union
 
 from alembic import op
@@ -13,8 +12,8 @@
 
 
 # revision identifiers, used by Alembic.
-revision: str = "09d011c1b387"
-down_revision: Union[str, None] = "8437ce954087"
+revision: str = '09d011c1b387'
+down_revision: Union[str, None] = '8437ce954087'
 branch_labels: Union[str, Sequence[str], None] = None
 depends_on: Union[str, Sequence[str], None] = None
 
diff --git a/backend/app/main.py b/backend/app/main.py
index aceeada7..5516f4bc 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -225,9 +225,7 @@ async def get_document(document_id: str, session: Session = Depends(get_session)
 async def get_total_population(
     document_id: str, session: Session = Depends(get_session)
 ):
-    stmt = text(
-        "SELECT * from get_total_population(:document_id) WHERE zone IS NOT NULL"
-    )
+    stmt = text("SELECT * from get_total_population(:document_id) WHERE zone IS NOT NULL")
     try:
         result = session.execute(stmt, {"document_id": document_id})
         return [
diff --git a/backend/tests/test_main.py b/backend/tests/test_main.py
index 396f5beb..8ada690a 100644
--- a/backend/tests/test_main.py
+++ b/backend/tests/test_main.py
@@ -406,6 +406,29 @@ def test_get_document_population_totals(
     assert data == [{"zone": 1, "total_pop": 67}, {"zone": 2, "total_pop": 130}]
 
 
+def test_get_document_population_totals_null_assignments(
+    client, document_id, ks_demo_view_census_blocks
+):
+    response = client.patch(
+        "/api/update_assignments",
+        json={
+            "assignments": [
+                {"document_id": document_id, "geo_id": "202090416004010", "zone": 1},
+                {"document_id": document_id, "geo_id": "202090416003004", "zone": 1},
+                {"document_id": document_id, "geo_id": "202090434001003", "zone": None},
+            ]
+        },
+    )
+    assert response.status_code == 200
+    assert response.json() == {"assignments_upserted": 3}
+
+    doc_uuid = str(uuid.UUID(document_id))
+    result = client.get(f"/api/document/{doc_uuid}/total_pop")
+    assert result.status_code == 200
+    data = result.json()
+    assert data == [{"zone": 1, "total_pop": 67}]
+
+
 def test_get_document_vap_totals(
     client, assignments_document_id_total_vap, ks_demo_view_census_blocks_total_vap
 ):