diff --git a/package.json b/package.json
index 5d6cb787..705b2696 100644
--- a/package.json
+++ b/package.json
@@ -59,6 +59,7 @@
         }
     },
     "dependencies": {
+        "color-rgba": "^2.3.0",
         "fs-extra": "^10.0.0",
         "klaw": "^3.0.0",
         "react-beautiful-dnd": "^13.1.0",
@@ -95,6 +96,7 @@
         "@traptitech/markdown-it-katex": "^3.4.3",
         "@traptitech/markdown-it-spoiler": "^1.1.6",
         "@trivago/prettier-plugin-sort-imports": "^2.0.2",
+        "@types/color-rgba": "^2.1.0",
         "@types/lodash.defaultsdeep": "^4.6.6",
         "@types/lodash.isequal": "^4.5.5",
         "@types/markdown-it": "^12.0.2",
diff --git a/src/components/ui/Header.tsx b/src/components/ui/Header.tsx
index 3492985a..f3b69134 100644
--- a/src/components/ui/Header.tsx
+++ b/src/components/ui/Header.tsx
@@ -31,8 +31,10 @@ const Header = styled.div<Props>`
     align-items: center;
     background-size: cover !important;
     background-position: center !important;
-    //background-color: var(--primary-header);
-    background-color: rgba(54, 54, 54, 0.75);
+    background-color: rgba(
+        var(--primary-header-rgb),
+        max(var(--min-opacity), 0.75)
+    );
     backdrop-filter: blur(10px);
     z-index: 20;
     position: absolute;
diff --git a/src/context/Theme.tsx b/src/context/Theme.tsx
index e5697881..c30fbbd0 100644
--- a/src/context/Theme.tsx
+++ b/src/context/Theme.tsx
@@ -1,3 +1,4 @@
+import rgba from "color-rgba";
 import { observer } from "mobx-react-lite";
 import { Helmet } from "react-helmet";
 import { createGlobalStyle } from "styled-components";
@@ -71,6 +72,8 @@ export type Theme = Overrides & {
     font?: Fonts;
     css?: string;
     monospaceFont?: MonospaceFonts;
+
+    "min-opacity"?: number;
 };
 
 export interface ThemeOptions {
@@ -287,7 +290,13 @@ const GlobalTheme = createGlobalStyle<{ theme: Theme }>`
 
 export const generateVariables = (theme: Theme) => {
     return (Object.keys(theme) as Variables[]).map((key) => {
-        return `--${key}: ${theme[key]};`;
+        const colour = rgba(theme[key]);
+        if (colour) {
+            const [r, g, b] = colour;
+            return `--${key}: ${theme[key]}; --${key}-rgb: ${r}, ${g}, ${b};`;
+        } else {
+            return `--${key}: ${theme[key]};`;
+        }
     });
 };
 
diff --git a/src/mobx/stores/helpers/STheme.ts b/src/mobx/stores/helpers/STheme.ts
index b2b20c4c..4a110e56 100644
--- a/src/mobx/stores/helpers/STheme.ts
+++ b/src/mobx/stores/helpers/STheme.ts
@@ -1,3 +1,4 @@
+import rgba from "color-rgba";
 import { makeAutoObservable, computed, action } from "mobx";
 
 import {
@@ -93,13 +94,15 @@ export default class STheme {
             ...PRESETS[this.getBase()],
             ...this.settings.get("appearance:theme:overrides"),
             light: this.isLight(),
+
+            "min-opacity": 1,
         };
     }
 
     @computed computeVariables(): Theme {
         const variables = this.getVariables() as Record<
             string,
-            string | boolean
+            string | boolean | number
         >;
 
         for (const key of Object.keys(variables)) {
@@ -204,15 +207,11 @@ export default class STheme {
 function getContrastingColour(hex: string, fallback?: string): string {
     if (typeof hex !== "string") return "black";
 
-    // TODO: Switch to color-parse
-    // Try parse hex value.
-    hex = hex.replace(/#/g, "");
-    const r = parseInt(hex.substr(0, 2), 16) / 255;
-    const g = parseInt(hex.substr(2, 2), 16) / 255;
-    const b = parseInt(hex.substr(4, 2), 16) / 255;
+    const colour = rgba(hex);
+    if (!colour) return fallback ? getContrastingColour(fallback) : "black";
 
-    if (isNaN(r) || isNaN(g) || isNaN(b))
-        return fallback ? getContrastingColour(fallback) : "black";
-
-    return r * 0.299 + g * 0.587 + b * 0.114 >= 0.186 ? "black" : "white";
+    const [r, g, b] = colour;
+    return (r / 255) * 0.299 + (g / 255) * 0.587 + (b / 255) * 0.114 >= 0.186
+        ? "black"
+        : "white";
 }
diff --git a/yarn.lock b/yarn.lock
index 688dfdfb..d07ef105 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1303,6 +1303,11 @@
     javascript-natural-sort "0.7.1"
     lodash "4.17.21"
 
+"@types/color-rgba@^2.1.0":
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/@types/color-rgba/-/color-rgba-2.1.0.tgz#0182795370deae5c2c62f71ea6e91c6bab87394d"
+  integrity sha512-tWcJLEiKdZ3ihJdThfLCe6Kw5vo0lgGcuucGkbtzcp1zifDA1E2Z96wxeSS/r+ytpHD15NCAWabX8GV911ywCA==
+
 "@types/debug@^4.1.6":
   version "4.1.7"
   resolved "https://registry.yarnpkg.com/@types/debug/-/debug-4.1.7.tgz#7cc0ea761509124709b8b2d1090d8f6c17aadb82"
@@ -1642,6 +1647,11 @@ ajv@^8.0.1, ajv@^8.6.0:
     require-from-string "^2.0.2"
     uri-js "^4.2.2"
 
+almost-equal@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/almost-equal/-/almost-equal-1.1.0.tgz#f851c631138757994276aa2efbe8dfa3066cccdd"
+  integrity sha1-+FHGMROHV5lCdqou++jfowZszN0=
+
 ansi-colors@^4.1.1:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/ansi-colors/-/ansi-colors-4.1.1.tgz#cbb9ae256bf750af1eab344f229aa27fe94ba348"
@@ -1934,11 +1944,34 @@ color-name@1.1.3:
   resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.3.tgz#a7d0558bd89c42f795dd42328f740831ca53bc25"
   integrity sha1-p9BVi9icQveV3UIyj3QIMcpTvCU=
 
-color-name@~1.1.4:
+color-name@^1.0.0, color-name@~1.1.4:
   version "1.1.4"
   resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.4.tgz#c2a09a87acbde69543de6f63fa3995c826c536a2"
   integrity sha512-dOy+3AuW3a2wNbZHIuMZpTcgjGuLU/uBL/ubcZF9OXbDo8ff4O8yVp5Bf0efS8uEoYo5q4Fx7dY9OgQGXgAsQA==
 
+color-parse@^1.4.1:
+  version "1.4.2"
+  resolved "https://registry.yarnpkg.com/color-parse/-/color-parse-1.4.2.tgz#78651f5d34df1a57f997643d86f7f87268ad4eb5"
+  integrity sha512-RI7s49/8yqDj3fECFZjUI1Yi0z/Gq1py43oNJivAIIDSyJiOZLfYCRQEgn8HEVAj++PcRe8AnL2XF0fRJ3BTnA==
+  dependencies:
+    color-name "^1.0.0"
+
+color-rgba@^2.3.0:
+  version "2.3.0"
+  resolved "https://registry.yarnpkg.com/color-rgba/-/color-rgba-2.3.0.tgz#d5eb481d7933d2542d1f222ea10ad40d159e9d35"
+  integrity sha512-z/5fMOY8/IzrBHPBk+n3ATNSM/1atXcHCRPTGPLlzYJ4fn7CRD46zzt3lkLtQ44cL8UIUU4JBXDVrhWj1khiwg==
+  dependencies:
+    color-parse "^1.4.1"
+    color-space "^1.14.6"
+
+color-space@^1.14.6:
+  version "1.16.0"
+  resolved "https://registry.yarnpkg.com/color-space/-/color-space-1.16.0.tgz#611781bca41cd8582a1466fd9e28a7d3d89772a2"
+  integrity sha512-A6WMiFzunQ8KEPFmj02OnnoUnqhmSaHaZ/0LVFcPTdlvm8+3aMJ5x1HRHy3bDHPkovkf4sS0f4wsVvwk71fKkg==
+  dependencies:
+    hsluv "^0.0.3"
+    mumath "^3.3.4"
+
 colorette@^1.3.0:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/colorette/-/colorette-1.3.0.tgz#ff45d2f0edb244069d3b772adeb04fed38d0a0af"
@@ -2742,6 +2775,11 @@ hoist-non-react-statics@^3.0.0, hoist-non-react-statics@^3.1.0, hoist-non-react-
   dependencies:
     react-is "^16.7.0"
 
+hsluv@^0.0.3:
+  version "0.0.3"
+  resolved "https://registry.yarnpkg.com/hsluv/-/hsluv-0.0.3.tgz#829107dafb4a9f8b52a1809ed02e091eade6754c"
+  integrity sha1-gpEH2vtKn4tSoYCe0C4JHq3mdUw=
+
 idb@^6.0.0:
   version "6.1.2"
   resolved "https://registry.yarnpkg.com/idb/-/idb-6.1.2.tgz#82ef5c951b8e1f47875d36ccafa4bedafc62f2f1"
@@ -3276,6 +3314,13 @@ ms@2.1.2:
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.1.2.tgz#d09d1f357b443f493382a8eb3ccd183872ae6009"
   integrity sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==
 
+mumath@^3.3.4:
+  version "3.3.4"
+  resolved "https://registry.yarnpkg.com/mumath/-/mumath-3.3.4.tgz#48d4a0f0fd8cad4e7b32096ee89b161a63d30bbf"
+  integrity sha1-SNSg8P2MrU57Mglu6JsWGmPTC78=
+  dependencies:
+    almost-equal "^1.1.0"
+
 nanoid@^3.1.30:
   version "3.1.30"
   resolved "https://registry.yarnpkg.com/nanoid/-/nanoid-3.1.30.tgz#63f93cc548d2a113dc5dfbc63bfa09e2b9b64362"