Add contrast helper

package.json

@@ -148,6 +148,7 @@
     "fast-text-encoding": "^1.0.6",
     "history": "^5.3.0",
     "hls.js": "^1.5.11",
+    "hsl-to-rgb-for-reals": "^1.1.1",
     "js-sha256": "^0.9.0",
     "jwt-decode": "^4.0.0",
     "lande": "^1.0.10",
@@ -201,6 +202,7 @@
     "tippy.js": "^6.3.7",
     "tlds": "^1.234.0",
     "tldts": "^6.1.46",
+    "wcag-contrast": "^3.0.0",
     "zeego": "^1.6.2",
     "zod": "^3.20.2"
   },
@@ -219,6 +221,7 @@
     "@react-native/typescript-config": "^0.74.1",
     "@testing-library/jest-native": "^5.4.1",
     "@testing-library/react-native": "^11.5.2",
+    "@types/hsl-to-rgb-for-reals": "^1.1.3",
     "@types/jest": "^29.4.0",
     "@types/lodash.chunk": "^4.2.7",
     "@types/lodash.debounce": "^4.0.7",
@@ -228,6 +231,7 @@
     "@types/react-dom": "^18.2.18",
     "@types/react-responsive": "^8.0.5",
     "@types/react-test-renderer": "^17.0.1",
+    "@types/wcag-contrast": "^3.0.3",
     "@typescript-eslint/eslint-plugin": "^7.18.0",
     "@typescript-eslint/parser": "^7.18.0",
     "babel-jest": "^29.7.0",