Using state

Input select card with select next service and custom color and icon for states. In the example below the icon mdi:cube-outline will be used when value is sleeping and mdi:cube in other cases.

Default behavior

If you don't specify any operator, == will be used to match the current state against the value

type: 'custom:button-card'
entity: input_select.cube_mode
icon: mdi:cube
tap_action:
  action: call-service
  service: input_select.select_next
  data:
    entity_id: input_select.cube_mode
show_state: true
state:
  - value: 'sleeping'
    color: var(--disabled-text-color)
    icon: mdi:cube-outline
  - value: 'media'
    color: rgb(5, 147, 255)
  - value: 'light'
    color: rgb(189, 255, 5)

With Operator on state

The definition order matters, the first item to match will be the one selected.

type: "custom:button-card"
entity: sensor.temperature
show_state: true
state:
  - value: 15
    operator: '<='
    color: blue
    icon: mdi:thermometer-minus
  - value: 25
    operator: '>='
    color: red
    icon: mdi:thermometer-plus
  - operator: 'default' # (1)!
    color: yellow
    icon: mdi: thermometer
    styles:
      card:
        - opacity: 0.5

1. Used when nothing matches (here any state > 15 and < 25)