I want to make a theme where a user can input one hexadecimal color for a theme. but a theme has made by various pre-defined color. So my question is that how to know offset between two colors code and using that offset generate a new color,
So for example:
If a user selects color code #110360
then theme header color should be #1c3ea4
. so now how to know offset between it, so if user change color then calculates a header color using that offset.
I am using sass to design theme
Thank you