fix(uui-color-picker): alpha should default to 100 if there is no color string

packages/uui-color-picker/lib/uui-color-picker.element.ts

@@ -74,7 +74,7 @@ export class UUIColorPickerElement extends LabelMixin('label', LitElement) {
   @state() private hue = 0;
   @state() private saturation = 0;
   @state() private lightness = 0;
-  @state() private alpha = 0;
+  @state() private alpha = 100;
   @state() private _colord: Colord = colord('hsl(0, 0%, 0%)');
 
   /**
@@ -361,7 +361,7 @@ export class UUIColorPickerElement extends LabelMixin('label', LitElement) {
     if (colorString === this.value) return;
 
     if (!colorString) {
-      this.alpha = 0;
+      this.alpha = 100;
       this.inputValue = '';
       this._value = colorString;
 
@@ -379,7 +379,7 @@ export class UUIColorPickerElement extends LabelMixin('label', LitElement) {
     this.hue = h;
     this.saturation = s;
     this.lightness = l;
-    this.alpha = this.opacity ? a * 100 : 100;
+    this.alpha = this.opacity ? a * 100 : 100; // Convert to 0-100 range, and set alpha to 100 if opacity is disabled
 
     const hslaColor = colorString as HslaColor;
 
@@ -395,7 +395,6 @@ export class UUIColorPickerElement extends LabelMixin('label', LitElement) {
     this.dispatchEvent(
       new UUIColorPickerChangeEvent(UUIColorPickerChangeEvent.CHANGE),
     );
-
     return true;
   }
 

packages/uui-color-picker/lib/uui-color-picker.story.ts

@@ -73,6 +73,7 @@ export const Inline: Story = {
 export const Opacity: Story = {
   args: {
     opacity: true,
+    value: undefined,
     inline: true,
   },
 };