feat(labels): assign random color when creating labels

Resolves F-591
Related discussion: https://community.vikunja.io/t/assign-a-random-color-to-a-new-label/348/7

src/helpers/color/randomColor.ts

@@ -0,0 +1,20 @@
+
+const COLORS = [
+	'#ffbe0b',
+	'#fd8a09',
+	'#fb5607',
+	'#ff006e',
+	'#efbdeb',
+	'#8338ec',
+	'#5f5ff6',
+	'#3a86ff',
+	'#4c91ff',
+	'#0ead69',
+	'#25be8b',
+	'#073b4c',
+	'#373f47',
+]
+
+export function getRandomColorHex(): string {
+	return COLORS[Math.floor(Math.random() * COLORS.length)]
+}

src/models/label.ts

@@ -5,15 +5,14 @@ import type {ILabel} from '@/modelTypes/ILabel'
 import type {IUser} from '@/modelTypes/IUser'
 
 import {colorIsDark} from '@/helpers/color/colorIsDark'
-
-const DEFAULT_LABEL_BACKGROUND_COLOR = 'e8e8e8'
+import {getRandomColorHex} from '@/helpers/color/randomColor'
 
 export default class LabelModel extends AbstractModel<ILabel> implements ILabel {
 	id = 0
 	title = ''
 	// FIXME: this should be empty and be definied in the client.
 	// that way it get's never send to the server db and is easier to change in future versions.
-	hexColor = DEFAULT_LABEL_BACKGROUND_COLOR
+	hexColor = ''
 	description = ''
 	createdBy: IUser
 	projectId = 0
@@ -25,6 +24,10 @@ export default class LabelModel extends AbstractModel<ILabel> implements ILabel
 	constructor(data: Partial<ILabel> = {}) {
 		super()
 		this.assignData(data)
+		
+		if (this.hexColor === '') {
+			this.hexColor = getRandomColorHex()
+		}
 
 		if (this.hexColor.substring(0, 1) !== '#') {
 			this.hexColor = '#' + this.hexColor