It's a common confusion about terminal colors... Actually we have this:
- plain ascii
- ansi escape codes (16 color codes with bold/italic and background)
- 256 color palette (216 colors+16gray + ansi) (colors are 24bit)
- 24bit true color (888 colors (aka 16 milion))
The 256 color palete is configured at start, and it's a 666 cube of colors, each of them defined as a 24bit (888 rgb) color.