Four shades
In one sentence
The original screen does not show color. Each pixel is one of four shades, stored as a number from 0 to 3. Two bits are enough for that.
The detail
A full-color painting has to be reduced before it can be a background. Artists working on the machine pick four tones and stick to them. Retroable's games do the same, because the hardware does not have a fifth shade.
The green cast people remember is the LCD, not a fifth color in the data. On a backlit emulator the same four values can look gray or green depending on the palette the emulator applies. The ROM still only stored 0, 1, 2, and 3.
Game Boy Color games can use a richer palette. Those are a different kind of ROM. A four-shade game is the original machine.
Worth keeping
- Each pixel is 0, 1, 2, or 3
- Two bits per pixel is the whole color depth
- The green look comes from the screen, not from extra colors in the file
Questions
Can I ask for a red character?
On the original machine, red becomes one of the four shades. There is no red channel.
Why does my emulator look gray instead of green?
The emulator chose a gray palette. The pixel values in the ROM did not change.
Is four shades the same as Game Boy Color?
No. Color games carry extra palette data. Original games do not.
Related
Game Boy is a trademark of Nintendo. Retroable is independent and is not affiliated with Nintendo.