diff --git a/source/content-scripts.ts b/source/content-scripts.ts
index a4c8b62..4ecfc06 100644
--- a/source/content-scripts.ts
+++ b/source/content-scripts.ts
@@ -11,6 +11,7 @@ import {
   runAnonymizeUsernamesFeature,
   runHideVotesFeature,
   runMarkdownToolbarFeature,
+  runUsernameColorsFeature,
 } from './scripts/exports.js';
 import Settings from './settings.js';
 import {extractGroups, initializeGlobals, log} from './utilities/exports.js';
@@ -70,6 +71,12 @@ async function initialize() {
     });
   }
 
+  if (settings.features.usernameColors) {
+    observerFeatures.push(() => {
+      runUsernameColorsFeature(settings);
+    });
+  }
+
   // Initialize all the observer-dependent features first.
   for (const feature of observerFeatures) {
     feature();
diff --git a/source/options/components/anonymize-usernames.ts b/source/options/components/anonymize-usernames.ts
index bb44c58..111a874 100644
--- a/source/options/components/anonymize-usernames.ts
+++ b/source/options/components/anonymize-usernames.ts
@@ -8,7 +8,8 @@ export function AnonymizeUsernamesSetting(props: SettingProps): TRXComponent {
       <p class="info">
         Anonymizes usernames by replacing them with "Anonymous #".
         <br />
-        Note that User Labels will still be applied to any usernames as normal.
+        Note that User Labels and Username Colors will still be applied to any
+        usernames as normal.
       </p>
     <//>
   `;
diff --git a/source/options/components/exports.ts b/source/options/components/exports.ts
index 7444aaf..93c830e 100644
--- a/source/options/components/exports.ts
+++ b/source/options/components/exports.ts
@@ -6,3 +6,4 @@ export {HideVotesSetting} from './hide-votes.js';
 export {JumpToNewCommentSetting} from './jump-to-new-comment.js';
 export {MarkdownToolbarSetting} from './markdown-toolbar.js';
 export {UserLabelsSetting} from './user-labels.js';
+export {UsernameColorsSetting} from './username-colors.js';
diff --git a/source/options/components/username-colors.ts b/source/options/components/username-colors.ts
new file mode 100644
index 0000000..806bbc8
--- /dev/null
+++ b/source/options/components/username-colors.ts
@@ -0,0 +1,153 @@
+import {html} from 'htm/preact';
+import {Component} from 'preact';
+
+import Settings from '../../settings.js';
+import {log} from '../../utilities/exports.js';
+import {Setting, SettingProps} from './index.js';
+
+type State = {
+  previewChecked: 'off' | 'foreground' | 'background';
+  usernameColors: UsernameColor[];
+};
+
+export class UsernameColorsSetting extends Component<SettingProps, State> {
+  constructor(props: SettingProps) {
+    super(props);
+
+    this.state = {
+      previewChecked: 'off',
+      usernameColors: [],
+    };
+  }
+
+  async componentDidMount() {
+    const settings = await Settings.fromSyncStorage();
+    this.setState({usernameColors: settings.data.usernameColors});
+  }
+
+  addNewColor = () => {
+    let id = 1;
+    if (this.state.usernameColors.length > 0) {
+      id = this.state.usernameColors.sort((a, b) => b.id - a.id)[0].id + 1;
+    }
+
+    const newColor: UsernameColor = {
+      color: '',
+      id,
+      username: '',
+    };
+
+    this.setState({
+      usernameColors: [...this.state.usernameColors, newColor],
+    });
+  };
+
+  removeColor = (targetId: number) => {
+    const usernameColors = this.state.usernameColors.filter(
+      ({id}) => id !== targetId,
+    );
+    this.setState({usernameColors});
+  };
+
+  saveChanges = async () => {
+    const settings = await Settings.fromSyncStorage();
+    settings.data.usernameColors = this.state.usernameColors;
+    await settings.save();
+  };
+
+  togglePreview = async () => {
+    let {previewChecked} = this.state;
+
+    // eslint-disable-next-line default-case
+    switch (previewChecked) {
+      case 'off':
+        previewChecked = 'foreground';
+        break;
+      case 'foreground':
+        previewChecked = 'background';
+        break;
+      case 'background':
+        previewChecked = 'off';
+        break;
+    }
+
+    this.setState({previewChecked});
+  };
+
+  onInput = (event: Event, id: number, key: 'color' | 'username') => {
+    const colorIndex = this.state.usernameColors.findIndex(
+      (color) => color.id === id,
+    );
+    if (colorIndex === -1) {
+      log(`Tried to edit unknown UsernameColor ID: ${id}`);
+      return;
+    }
+
+    const newValue = (event.target as HTMLInputElement).value;
+    this.state.usernameColors[colorIndex][key] = newValue;
+    this.setState({usernameColors: this.state.usernameColors});
+  };
+
+  render() {
+    const {previewChecked, usernameColors} = this.state;
+    usernameColors.sort((a, b) => a.id - b.id);
+
+    const editors = usernameColors.map(({color, id, username}) => {
+      const style: Record<string, string> = {};
+      if (previewChecked === 'background') {
+        style.backgroundColor = color;
+      } else if (previewChecked === 'foreground') {
+        style.color = color;
+      }
+
+      const usernameHandler = (event: Event) => {
+        this.onInput(event, id, 'username');
+      };
+
+      const colorHandler = (event: Event) => {
+        this.onInput(event, id, 'color');
+      };
+
+      const removeHandler = () => {
+        this.removeColor(id);
+      };
+
+      return html`
+        <div class="username-colors-editor" key=${id}>
+          <input style=${style} value=${username} onInput=${usernameHandler} />
+          <input style=${style} value=${color} onInput=${colorHandler} />
+          <button class="button destructive" onClick=${removeHandler}>
+            Remove
+          </button>
+        </div>
+      `;
+    });
+
+    return html`
+      <${Setting} ...${this.props}>
+        <p class="info">
+          Assign custom colors to usernames.
+          <br />
+          You can enter multiple usernames separated by a comma if you want them
+          to use the same color.
+        </p>
+
+        <div class="username-colors-controls">
+          <button class="button" onClick=${this.addNewColor}>
+            Add New Color
+          </button>
+
+          <button class="button" onClick=${this.togglePreview}>
+            Toggle Preview
+          </button>
+
+          <button class="button" onClick=${this.saveChanges}>
+            Save Changes
+          </button>
+        </div>
+
+        ${editors}
+      <//>
+    `;
+  }
+}
diff --git a/source/options/features.ts b/source/options/features.ts
index c577dc7..eba7d73 100644
--- a/source/options/features.ts
+++ b/source/options/features.ts
@@ -7,6 +7,7 @@ import {
   JumpToNewCommentSetting,
   MarkdownToolbarSetting,
   UserLabelsSetting,
+  UsernameColorsSetting,
 } from './components/exports.js';
 
 /**
@@ -59,6 +60,12 @@ export const features = [
     value: 'User Labels',
     component: () => UserLabelsSetting,
   },
+  {
+    index: 0,
+    key: 'usernameColors',
+    value: 'Username Colors',
+    component: () => UsernameColorsSetting,
+  },
   {
     index: 1,
     key: 'debug',
diff --git a/source/scripts/exports.ts b/source/scripts/exports.ts
index 05381ac..bb2d568 100644
--- a/source/scripts/exports.ts
+++ b/source/scripts/exports.ts
@@ -5,3 +5,4 @@ export * from './hide-votes.js';
 export * from './jump-to-new-comment.js';
 export * from './markdown-toolbar.js';
 export * from './user-labels.js';
+export * from './username-colors.js';
diff --git a/source/scripts/username-colors.ts b/source/scripts/username-colors.ts
new file mode 100644
index 0000000..20e4d89
--- /dev/null
+++ b/source/scripts/username-colors.ts
@@ -0,0 +1,45 @@
+import Settings from '../settings.js';
+import {log, querySelectorAll} from '../utilities/exports.js';
+
+export function runUsernameColorsFeature(settings: Settings) {
+  const count = usernameColors(settings);
+  log(`Username Colors: Applied ${count} colors.`);
+}
+
+function usernameColors(settings: Settings): number {
+  const usernameColors = new Map<string, string>();
+  for (const {color, username: usernames} of settings.data.usernameColors) {
+    for (const username of usernames.split(',')) {
+      usernameColors.set(username.trim().toLowerCase(), color);
+    }
+  }
+
+  let count = 0;
+  const usernameElements = querySelectorAll<HTMLElement>(
+    '.link-user:not(.trx-username-colors)',
+  );
+
+  for (const element of usernameElements) {
+    if (element.classList.contains('trx-username-colors')) {
+      continue;
+    }
+
+    let target =
+      element.textContent?.replace(/@/g, '').trim().toLowerCase() ??
+      '<unknown>';
+    if (settings.features.anonymizeUsernames) {
+      target = element.dataset.trxUsername?.toLowerCase() ?? target;
+    }
+
+    element.classList.add('trx-username-colors');
+    const color = usernameColors.get(target);
+    if (color === undefined) {
+      continue;
+    }
+
+    element.style.color = color;
+    count += 1;
+  }
+
+  return count;
+}
diff --git a/source/scss/_settings.scss b/source/scss/_settings.scss
index 8387b5b..8becd88 100644
--- a/source/scss/_settings.scss
+++ b/source/scss/_settings.scss
@@ -124,4 +124,28 @@
     list-style: square;
     padding: 8px 8px 8px 24px;
   }
+
+  .username-colors-controls {
+    display: grid;
+    gap: 8px;
+    grid-template-columns: repeat(3, 1fr);
+  }
+
+  .username-colors-editor {
+    display: grid;
+    gap: 8px;
+    grid-template-columns: auto auto min-content;
+    margin-top: 8px;
+
+    input {
+      background-color: var(--background-primary);
+      border: 1px solid var(--blue);
+      color: var(--foreground);
+      padding: 8px;
+    }
+
+    .button {
+      min-width: 10rem;
+    }
+  }
 }
diff --git a/source/settings.ts b/source/settings.ts
index a8e26c1..83dbb40 100644
--- a/source/settings.ts
+++ b/source/settings.ts
@@ -56,6 +56,7 @@ export default class Settings {
     knownGroups: string[];
     latestActiveFeatureTab: string;
     userLabels: UserLabel[];
+    usernameColors: UsernameColor[];
   };
 
   public features: {
@@ -68,6 +69,7 @@ export default class Settings {
     jumpToNewComment: boolean;
     markdownToolbar: boolean;
     userLabels: boolean;
+    usernameColors: boolean;
   };
 
   private constructor() {
@@ -118,6 +120,7 @@ export default class Settings {
       ],
       latestActiveFeatureTab: 'debug',
       userLabels: [],
+      usernameColors: [],
     };
 
     this.features = {
@@ -129,6 +132,7 @@ export default class Settings {
       jumpToNewComment: true,
       markdownToolbar: true,
       userLabels: true,
+      usernameColors: false,
     };
   }
 
diff --git a/source/types.d.ts b/source/types.d.ts
index f1ae50d..a6b391f 100644
--- a/source/types.d.ts
+++ b/source/types.d.ts
@@ -27,4 +27,10 @@ declare global {
     text: string;
     username: string;
   };
+
+  type UsernameColor = {
+    color: string;
+    id: number;
+    username: string;
+  };
 }