Fix labels randomly changing color after saving

src/helpers/color/colorFromHex.js

@@ -0,0 +1,13 @@
+/**
+ * Returns the hex color code without the '#' if it has one.
+ *
+ * @param color
+ * @returns {string}
+ */
+export const colorFromHex = color => {
+	if (color.substring(0, 1) === '#') {
+		color = color.substring(1, 7)
+	}
+
+	return color
+}

src/helpers/color/colorFromHex.test.js

@@ -0,0 +1,11 @@
+import {colorFromHex} from './colorFromHex'
+
+test('hex', () => {
+	const color = '#ffffff'
+	expect(colorFromHex(color)).toBe('ffffff')
+})
+
+test('no hex', () => {
+	const color = 'ffffff'
+	expect(colorFromHex(color)).toBe('ffffff')
+})

src/helpers/color/colorIsDark.js

@@ -0,0 +1,18 @@
+export const colorIsDark = color => {
+	if (color === '#' || color === '') {
+		return true // Defaults to dark
+	}
+
+	if (color.substring(0, 1) !== '#') {
+		color = '#' + color
+	}
+
+	let rgb = parseInt(color.substring(1, 7), 16)   // convert rrggbb to decimal
+	let r = (rgb >> 16) & 0xff  // extract red
+	let g = (rgb >> 8) & 0xff  // extract green
+	let b = (rgb >> 0) & 0xff  // extract blue
+
+	// luma will be a value 0..255 where 0 indicates the darkest, and 255 the brightest
+	let luma = 0.2126 * r + 0.7152 * g + 0.0722 * b // per ITU-R BT.709
+	return luma > 128
+}

src/helpers/color/colorIsDark.test.js

@@ -0,0 +1,16 @@
+import {colorIsDark} from './colorIsDark'
+
+test('dark color', () => {
+	const color = '#111111'
+	expect(colorIsDark(color)).toBe(false)
+})
+
+test('light color', () => {
+	const color = '#DDDDDD'
+	expect(colorIsDark(color)).toBe(true)
+})
+
+test('default dark', () => {
+	const color = ''
+	expect(colorIsDark(color)).toBe(true)
+})