Dyes...
Yes, you can buy dyes on the trading post for in game coin that are colors you want. I never buy those gem store RNG dye packs due to the odds of getting some low value dye I don’t need or want. You can also craft unidentified dyes of various colors with Chef. However as an unidentified dye the final result may not be what you want and the mats are often more valuable than the dye.
The wiki has lists of dyes if you are not sure what their names are on the TP:
https://wiki.guildwars2.com/wiki/Dye#Colors
Also while shopping the TP for dyes you can use the preview function to get an idea of what they look like before buying.
The Burninator
(edited by JustTrogdor.7892)
You can use this tool:
https://www.gw2bltc.com/en/tool/dye/search
to find dyes to your liking within your price range.
John Smith: “you should kill monsters, because killing monsters is awesome.”