...

This is a much more subtle effect, and one that really shouldn't matter as much as I am caring, but I've wanted to do this since last Fall, haha. So, if you've played a game like the Genesis/Mega Drive Sonics, you might've noticed it has an effect where it fades in from black. If you study it, however, it looks kind of... odd? The Amazing Sonic 3 Unlocked Blog has a post explaining the effect. Given I am working in the world of a faux-16-bit machine, having my screen transitions work like I'm actually fiddling with the color palette is a very desirable trait.

My current solution is simple, in hindsight. I made a sprite sheet of full screen colors, filling the blue, green, and red channels one after another. Attached here is a GIF, but for GMS2 I found it easier to make a comically wide 6400 image, haha.

Then, I fiddle with the blendmode to emulate the "multiply" effect in common image editors. It's not quite how a palette effect would look, but at this stage of me knowing how to make stuff, this is the best I can figure. It looks pretty good, I'd say!