Dyes

[Sagittarian]

There are other dyes not mentioned in the guide jabberwocks linked. Those can be made by DoH after, I think, level 30.

And a correction in the materia guide - FSH don't collect carbonized matter.

To answer the original question in the most vague form, right click and select the convert/dye/meld option from the menu. On a PS3, hit square to open the item menu.
For melds, you can request melds from other players, just like requesting a trade. You select the item, materia, and payment. The crafter just has to hit accept.

[Umo]

There are other dyes not mentioned in the guide jabberwocks linked. Those can be made by DoH after, I think, level 30.

And beastmen tribes vendors once unlocked