Jumping in on the conversation about getting traditional media into digital --
I do traditional watercolors and have done a lot of experimenting with trying to get the best digital copy. I've tried good cameras with studio lights, scanners, my iPhone, and various digital means to get the inevitable gray out. If it's on hot press, scanning seems to work the best (if you have a decent scanner) but cold press is hard because of the texture.
Currently, I get the best results using my iPhone and photographing it in the most neutral light I can find. (Inside my house with indirect light around noon seems often to be the most neutral temperature light.) I then adjust the white balance, contrast, etc. with several different apps. You can do a lot in Snapseed, a free app for the iPhone, because it allows you to select individual colors on the painting and adjust the brightness/contrast etc of just that one color. I also sometimes take it into Procreate and select the white sections of the paper (which is often too gray) using the autoselect and threshold adjustment and replace it with white.
Here, for example, are a before and after of a quick watercolor sketch I did of the Guggenheim when I went to NYC. This was all with my iPhone camera and Snapseed. I could have messed with it even more but it was just a sketch and I mainly wanted the white of the Guggenheim to show up.
By the way, Alicia Armadilla, a wonderful line and wash professional artist, does all of her scans with just an iPhone and Snapseed.
Hope that helps.