Easily find Shading Colours
I am not into colour theory – having worked by instinct most of the time – so picking the shading colours to me is not a big decision.
Start with a simple shape in your base colour.
Add two more shapes overlapping the base shape in colours you want to use for shading.
I prefer to avoid plain white and black for the shading.
Change the opacity of the shader objects to get a mixed colour.
Duplicate the shader objects and change the level of opacity.
They don’t need to align – it can even be helpful for them to overlap to find the right colour.
Grouping all the light coloured shaders and the dark ones allows you to quickly change colours.
Using the colour picker you can now choose a colour from your ‘shader objects’ with one click.
This is a version using 10% differences and a cleaner layout. Using a couple of these with the base colours of your illustration above your design are will allow quick picking of matching colours.