How do I make a color changing shader?

I'm trying to make a Pizza Tower Engine for free use in Construct 3 as I cannot afford the final game and I want to try and play it even if unofficially. If anything this is more of a challenge because most of the Pizza Tower engines aren't very accurate.

I know that all of Peppino's sprites are yellow and I want to add the costume system to the game like it is in certain builds and fangames. I'm focusing only on the palettes for now but if you know a solution for the patterns I'll add those as well.

sorry for late response but

if you want to add COLOR palettes, make a global variable called "palettes" or something, and give the sprites of the player the "replace color" effect, and if the player is overlapping the dresser and the up key is pressed, add 1 to palettes. if the palettes is greater than the palette limit (example:9) set value to 0. for each palette, do a compare variable and set the value to the desired number and for the actions, do set effect paremeter and for the colors, do rgbex(0,0,0) (replace the 0s with color numbers from 0-100, for 255, do rgb255(0,0,0))

will post a screenshot of this later