Set my own custom colors

[walrus543]

Hello,
Months ago I created the Pure Black Blue theme (inspired by the Pure Black Red theme).
Today I upgraded my device to Android 17 and I wanted to tweak the colors.
Either I don't remember how to set my own custom colors or it's no longer possible...
Thanks for your help.

EDIT: found.
Settings > 3 dots > Advanced settings > Replace colors manually.