In Cheese Jump, the player is a truckle with a slice taken out. "Truckle" is the word for a wheel of cheese.
The player was added to the game in "Basic Doodle Jump", the base code for Cheese Jump. In "Basic doodle jump" (Modified), Ian changed the color of the player to yellow to make it easier to focus on. Ian's friend commented on how it kind of looked like cheese and that he should make it into a block of cheese, but he didn't know how to do that.
Later in "Less basic doodle jump" Seth changed the player so that it was split into three sections and Ian set the top one to yellow (#fcff45) and the bottom two to orange (#e0ad02) [2]. In Cheese Jump Alpha the player was fully redesigned into the truckle we all know and love today.
Burnt Yellow: #e0ad02
Canary Yellow: #fcff45
Black: #000000
Canary yellow makes up most of the truckle, Burnt Yellow makes up the inside of the slice taken out, and Black is the outline.
In reverse mode, the colors are:
Blue Orchid: #1f52fd
Medium Blue: #0300ba
White: #ffffff
Blue Orchid makes up most of the truckle, Medium Blue makes up the inside of the slice taken out, and White is the outline.