Hey there, sorry for the incredibly late answer T__T <3 Thank you so much for liking my style, that makes me so happy!! ; w; My absolute favorite program for digital drawing has to be Paint Tool SAI, closely followed by Clip Studio Paint.  The latter is great for making comic pages!  Some tips for coloring that I really feel has helped me:



1.  Using a flat brush instead of a round one for more interesting strokes

2.  Using different hues when coloring light and shadow, rather than just picking a lighter or darker tone of the same hue. 

3.  Playing with different blend modes for the layers when doing light, shadow and glows - such as luminosity, multiply, overlay and color dodge! 

4.  Not overblending the colors

5.  Applying colors on a background that isn’t always white, but more of a medium or darker tone, depending on what mood you’re going for in the picture- from the beginning!  Some time back, I would always apply colors to lineart on a white background, then try editing in some kind of color later, but then I would have a hard time making it all fit nicely together.  This tip helped me a lot! 



I still have A LOT to learn about coloring, I realize, but I learned these tips from different people over time and they all really helped me, so I hope that maybe they could be beneficial to you too!  Thank you so much for your message ;-; <3