Super Mario Bros. (TechEruo's Unreleased Commodore 64 port)

Colors
The game utilizes all 16 of the Commodore 64's colors at least once.

Black

 * Buzzy Beetle (Shell)
 * Night Backdrop

White

 * Snow

Red

 * Mario (Overalls & Hat)

Cyan

 * "Transparent" Water

Violet

 * Peach's Dress

Green

 * Trees/Bushes

Blue

 * Underground Blocks

Yellow

 * Bowser (Skin)

Orange

 * Goomba (Legs)

Brown

 * Goomba (Skin)

Light Red

 * Fire Mario (Overalls & Hat)

Dark Grey

 * Goomba (Castle Palette)

Medium Grey

 * Castle Walls

Light Green

 * Luigi (Overalls & Hat)

Light Blue

 * Overworld Backdrop

Light Grey

 * Pipes (Castle Palette)