Nice visualizations - have you tried Rebelle? They have an online version that lets you play with the watercolor/brushes of the painting software so you can see the colors drying on the canvas.

https://www.escapemotions.com/experiments/rebelle/index.php

I never got into rebelle, though this demo is pretty cool.

I used to use expressii, and always thought it was one of the most under rated painting apps. Has a very natural feel to it.

https://www.expresii.com/

That's super neat looking - I really like the demonstrations of Chinese calligraphy with the brushes as well.

Oooh yeah I forgot how incredible that was! They really put care into how the pigments mix and move. I used to love watching timelapses of people doing art in rebelle.