Color studies for a tomato.
Creating color studies has been long, boring, and tedious... then again mixing paint can be exciting.
It can also be terrifying when you realized you just wasted a large amount of expensive watercolor paint to end up with a color you don't want. So make sure to put a swatch in your color studies swatch book, and note which colors, proportions, brands, etc.,
I remembered that I had fresh on the vine tomatoes in my kitchen...
In the end color mixing and creating all of those swatches has become well worth the effort. The last time I did any serious color studies, that involved mixing my own paints, etc., was a good twenty plus years ago.
If you've never mixed colors before I highly recommend doing so, there are plenty of color mixing books available in the art book market to help get you started.