Add more colours for users to choose from

[DanWin]

[Artifact0]

The chat already allows any RGB hex color value to be passed while logging in, but only gives the user a list to choose from. An input can be offered where a six digit alphanumeric string could be sanitized and used as color code, or else thrown out if invalid to prevent abuse. a nonlinear color chooser could be integrated as an alternative to random or the color presets, perhaps like the one in the profile menu.