color yourself

package/contents/ui/lib/helper.js

@@ -1,13 +1,3 @@
-const colors = [
-  '#f00', '#e21c00', '#c83800', '#a50', '#8d7100',
-  '#718d00', '#6fa100', '#5c8000', '#498000', '#080'
-];
-
-const batteryColor = batteryPercent => colors[({
-  "-2": 9,
-  "-1": 0
-})[batteryPercent] ?? ~~(batteryPercent / 10 + 0.5) - 1];
-
 const batteryLevel = batteryPercent => ({
   "-2": "not connected",
   "-1": "charging"
@@ -17,3 +7,14 @@ const batteryIcon = batteryPercent => ({
   "-2": "action-unavailable",
   "-1": "battery-ac-adapter"
 })[batteryPercent] ?? "audio-headphones-symbolic";
+
+const interpolateColor = (c0, c1, f) => { // https://stackoverflow.com/a/63775249
+  if(isNaN(f)) return "transparent";
+  c0 = c0.replace('#', '').match(/.{1,2}/g).map(oct => parseInt(oct, 16) * (1-f));
+  c1 = c1.replace('#', '').match(/.{1,2}/g).map(oct => parseInt(oct, 16) * f);
+  return "#" + [0, 1, 2]
+    .map(i => Math.min(Math.round(c0[i] + c1[i]), 255))
+    .reduce((a, v) => ((a << 8) + v), 0)
+    .toString(16)
+    .padStart(6, "0");
+};