I’m putting together a skin of my own. If I add a gauge to a dashboard with the default skin then it works fine. If I do it with my own skin then the gauge ‘animates’ up to the right temperature when I load the dashboard and then the color part disappears and I’m just left with the bgcolor:
kitchen_temp:
widget_type: gauge
entity: sensor.temperature_5
min: 0
max: 40
color: ffffff
bgcolor: ff0000
units: °C
This is what I see after the animation bit finishes.