Why is the xlibc palette like this?

[Bobb56]

Hello,
I was wondering how to convert an RGB color to an index in the xlibc palette.
According to my analysis, the palette indices are associated with their colors as follows:
2 bits for red, then 3 bits for blue and 3 bits for green.
This means there are half as many shades of red as there are of blue and green. The result is a palette with many shades of blue that are not very distinguishable, and very few shades of red.
However, according to my research, the color whose variations are least perceived by the human eye is blue, not red.
Wouldn't it have been better to store blue on 2 bits, and green and red on 3 bits?

[mateoconlechuga]

It's the "xlibc" palette. This is from the xLIBC library on the TI 84+CSE. It was primarily for ease of use for people transitioning to writing programs on the TI84+CE calculators. The palette itself was originally used because it was easy to generate, the high byte equals the low byte of the 16-bit color value.

You can change the palette as needed to anything you want, or use convimg to create a palette from a collection of images.

[mateoconlechuga]

It sounds like you might not have read the documentation yet about how to set custom colors, so here is that page: https://ce-programming.github.io/toolchain/libraries/graphx.html#overview

[Bobb56]

Thank you for your reply.
I have read the documentation several times and I know that I can change the palette, but I wanted to know why the default palette was like that.