Martin Damgaard proposed an idea for a universal bitcoin value color scale in an attempt to solve the decimal problem of small bitcoin amounts identified by BIP176 Bits denomination proposal which he used as a template.
The issue with this according to Kharl-Johan Alm is that by the time people adopt this method, it will only give a false high value to the amount make it bigger than it really is, which is misleading.
Another problem is that different UX colours have different meanings and colours don’t work well with text. Also, colour blind users may find it difficult.
BIP176 is widely accepted anyway. It also makes it easier to read bitcoin amounts up to 8 decimal places than colours . Besides, the proposed method is cumbersome and most wallets may not adopt it because it will make their design look substandard.