Peters Well if you are on business and using the bunq card, it could look kind childish.
Maybe this idea is because all the banks offer their cards with dark/1color.
Bunq is indeed unique with their 12coloured rainbow on it.
But it depend on your taste if you like it or not.
I am using bunq free and keeping anotjer bank as main use.😅
If bunq redesign the cards (just let us choose the color) and implement some stuff I will be fully switched😁