Ignore brightness for turned off light

[andreypolyak]

Checklist

• I updated the card to the latest version available
• I cleared the cache of my browser

Describe the bug
I have a horizontal stack with two buttons to control lights (please see below YAML configuration and screenshot). The first light doesn't have a brightness attribute when it is turned off:

The second one has it:

Because of that, the button for the second light is filled in black color when in fact they don't have any difference in their real state -- they are both turned off:

The style for the first button:
style="--button-card-light-color:var(--paper-card-background-color); --button-card-light-color-no-temperature:var(--paper-card-background-color);"

The style for the second button:
style="--button-card-light-color:rgb(16, 16, 18); --button-card-light-color-no-temperature:rgb(16, 16, 18);"

If I manually update the state for the second light and delete the brightness attribute:

Both buttons start to have the same color:

And the same style:
style="--button-card-light-color:var(--paper-card-background-color); --button-card-light-color-no-temperature:var(--paper-card-background-color);"

Version of the card
Version: 3.3.6

To Reproduce
This is the configuration I used:

    - type: custom:button-card
      name: Theo
      entity: light.group_bedroom_top_theo
      color: auto
      color_type: card
      icon: mdi:lightbulb
      show_label: false
      show_name: true
      hold_action:
        action: more-info
        entity: light.group_bedroom_top_theo
        haptic: success
      tap_action:
        action: call-service
        service: script.fire_custom_event
        service_data:
          custom_event_data: group_bedroom_top_theo_virtual_switch_individual_toggle
        haptic: success
      styles:
        card:
          - height: 72px
    - type: custom:button-card
      name: Bedroom
      entity: light.bedroom_wardrobe
      color: auto
      color_type: card
      icon: mdi:wardrobe-outline
      show_label: false
      show_name: false
      hold_action:
        action: more-info
        entity: light.bedroom_wardrobe
        haptic: success
      tap_action:
        action: call-service
        service: script.fire_custom_event
        service_data:
          custom_event_data: bedroom_wardrobe_virtual_switch_individual_toggle
        haptic: success
      styles:
        card:
          - height: 72px

Expected behavior
Ignore the brightness of the turned-off light when computing the color for the button.

Desktop (please complete the following information):

• Browser Chrome
• Version 85.0.4183.121 (Official Build) (64-bit)

[RomRider]

Fixed in 3.4.0-1. Enable the beta versions for button-card in HACS to see it.