There is a BUG where the item: Cloth Dye, Dark Green : found in the market at Ziggurat, turnes the cloth a medium blue color. IDK if thats just the color they wanted or a BUG so I'd thought I'd report it. Sorry if its been taken note of already. Thanks.
This has been a prob since the Underdark. SO many colors are just not right.
Leather Dye: Svirfineblin Red is also bugged, it is actually a green color.
Many of these (namely, the custom ones) are bugged but apparently there's also some mismatch between dye names and colours. Dark Green (#48) is a BioWare item which, according to this chart (http://wiki.avlis.org/DynamicDyeColorChart), is really a turqoise (compare #29).
May I suggest scrapping the dye in favour of the Ranger Green Cloth dye that was available in the UD ranger shop and is a proper dark green?