This might be a bit out there, but I was wondering if it makes sense to include a “Colour/Color” field type. I think if there is a possibility of colouring cards in the future, it might be good to be able to predefine the colours in some way and then have that value as the colour rather than having to explicitly define this in every view from scratch. I feel this enables long-term customization/consistency better.
If this is something that has support, I would also suggest that it would be really great if there are set of formulas that work with colours (produce colours based on RGB values, CSS colours, fade/darken colour, etc.) that would return colour objects as their output (inspired by Power Apps colour functions).
As usual, I may have gotten carried away in my ask 
