Oh no 
This can be done. Create class with gradient background similar to original what the plate using , but with brighter colors. And then watch the input msg with some parameter and add that class to the plate element. Or create button inside widget to toggle that class.
That's a good question.
The art in HTML/CSS is many many steps behind from what digital artists do. Thus I do watch tutorials about Illustrator and Photoshop and similar. There is may things what can't be translated to HTML/CSS but mostly the things are achievable. And then it takes to know or learn some CSS tricks.
I'm not good at the art at all but I can do replicas. So I take some good looking things and try my best to achieve something similar.
I don't know when it's finished. That would take years of learning art, which I'll probably miss. Too late for that for me.
