The Icon File Format

Reverse engineering a file format:

• There are only 16 colors available and the icon size is 32 x 32 pixels.
• Build an icon using the entire palette of colors available.
• Distribute the colors in such a way that you can identify them from the coding.
• We can identify the colors by how many pixels each one occupies:

The image actual size.

Can you figure out the code from this side-by-side comparison?

The code.	The image enlarged.