The iconColor property in the label card gets sent to the oh-icon component which renders the card’s icon. How that component handles the color depends on the type of icon you are using. That looks like the f7 thermometer icon on the label card, so the oh-icon uses the f7 icon color system. F7 doesn’t accept arbitrary colors, it only accepts colors from a limited list of color name strings in the library:
If you just change the #00cc66 in your expression to green you’ll see three colors instead of two. The f7 green, however is #4cd964, so it will be a little different than the one you are using for the gauge, if that matters to you.
No, the codes will never work in f7, only the names. This is related to the way f7 uses classes to do all the basic color assignment. The codes are just there in the docs to show exactly which shade corresponds to each color name.
I’ve never tested them systematically, but I’m a little surprised they don’t all work. It’s possible there are certain restrictions for particular colors, but it would be strange for those restrictions to apply to icons.
It may be a problem with my hardware, but I can’t tell the difference between “pink” and “red” here.
All other colors are displayed correctly.
red OK
green OK
blue OK
pink same as 'red'
yellow OK
orange OK
purple OK
deeppurple OK
lightblue OK
teal OK
lime OK
deeporange OK
gray OK
white OK
black OK