As mentioned in a few previous news posts, a forum member here, Enko, is compiling dye guides for various professions. You can find his completed work here: Mesmer, Necromancer, Elementalist.
He is also requesting contributions of screenshots to complete his guides for the Ranger, Warrior, Dervish, Paragon professions. If you're interested in contributing to our GuildWars community, now's your chance!
Don't forget that the Triple Dye Weekend is almost upon us, so you will have more of a chance to find dyes. All screenshots should be taken from the Dye Preview Window in-game, so no dyes need be actually spent. If you cannot afford dyes of your own, Enko offers to loan you dyes for the purpose of this project.
For more information, click on the links to the specific profession's threads above.