I welcome this opportunity to say that I definitely endorse
Hotbunlily's previous statement.
I can confirm that you definitely know both how to get the most out of the color spectrum and how to use it to your advantage in your artworks.
Your "Watercolor Starmie" artwork is a fine example, underlining the previous statements:
Starmie's jewel is of course the main focal point of the artwork and the range of color continuously expands the further away it moves from Starmie's center core.
The "stain-glass window" style that you used for this artwork also significantly allowed you to play with the lighting and place additional emphasis on the color spectrum.
In addition to this, Starmie's Pokédex entry in Pokémon X states that its "central core glows with the seven colors of the rainbow".
Who knows? Maybe it could be interesting for your future self to try and recreate this artwork with actual stained glass and let the sunlight shine through it?
I think that it'd be only fitting since Starmie can have the "Illuminate" ability!
You can actually create a lot of fascinating effects with light and stained glass:
Church architects use this to their advantage as well in order to create a safe and quiescent atmosphere, allowing the church visitors to focus on their prayers for example.
Either way, I wish you good luck and (more importantly) lots of fun with experimenting and working on future projects that have yet to see "the light of day".