While it won’t help those on Officials or Consoles obviously, the PC mod you might want to check out that does this is CharEditLite, and it would be wonderful if its functionality was incorporated into the base game.
In terms of what it allows? Pretty much everything. Server admins even have menu options to enable players to have access to color controls outside the normal ranges and a separate option to enable the sliders to go past their normal ranges (both default to disabled). With such options, you could have pink hair like @Berserker wants, or make yourself or your thrall as big as Ladagara. Customization of workbench thralls is also possible.
Additionally it has a mechanism that allows you to save appearances to in-game items (shards) or even copy the values so you can paste them into a text file or from a text file into the editor.