Interesting concept with a lot of potential. Like others already pointed out, there are a few quality-of-life improvements you could make, such as having dedicated keybinds for each color and showing the color order in some way.
I also think there are some interesting ways you could use this mechanic to scale the difficulty in later levels, such as intentionally choosing the wrong color to jump through certain blocks while changing the player's color mid-air.
The player controller could also use some work to make it feel smoother and more responsive.
Overall, it's a great concept with decent execution. Good job!