How I can dye my chocobo? (racing)

I loved my companion was dalamud red

I don't like ride yellow...I saw other players had colors.
I wanted dye for my chocobo racing

The racing choco just is what it is. To get a new color you need a whole new choco, can't customise that unfortunately.

When you breed a racing chocobo, it randomly takes the colour of one of its parents. Chocobos hired from the Gold Saucer for breeding (via Covering Permissions) will have a random colour, which is the only way to introduce new colours. There is no way to change the colour of an existing racing chocobo, unfortunately.