Can't get Bubble Card to change it's colours

I’m using Bubble Card from @Cloos and all is just peachy but try as I might I can’t get the colours to change.
I’m getting a nice yellow when (say) a switch is on and a subtle grey when its off but I’d like to highlight some switches differently. Maybe Red when it’s on and Blue when it’s off etc.
I’ve setup a really simple single entity card for testing but try as i might when I adjust anything in the Styling options nothing changes. I mean the switch still works but it’s yellow/grey no matter how I set it.
I’ve noted I need to clear the cache which I have done repeatedly - but nothing changes.
Anyone have a clue what I’m doing wrong?

Hi! Can you share the custom style/template you have tried?

Sure, here it is:

type: custom:bubble-card
card_type: button
entity: input_boolean.user_presence_nick
name: Nick
button_action:
tap_action:
action: toggle
styles: |-
type: custom:bubble-card
card_type: button
entity: input_boolean.user_presence_nick
name: Test
styles: |
.bubble-button-background {
opacity: 1 !important;
background-color: ${state === ‘on’ ? ‘blue’ : ‘red’} !important;
}

Sorry to ask again but I just can’t seem to fathom this one @Cloos any help you can give much appreciated.

I can make the color change in light entities but it doesn’t work for me in switch entities. Not sure if I’m doing it right, I’m new to BubbleCard.

More info, the switch card keeps the new color when it is off. Once it is on it stays in the new color briefly (about half a second) and then changes to the default color (orange).