I would say that the green is to dark.
Unfortunaltely, nobody has taken the trouble to post a overview of available plant colours on the net... :\

Woad and Weld were commonly used dyestuffs, obtaining Blue and Yellow respectively, and *VERY* colorfast. The combination of the two yields a nice Forest Green, with a lot of different varients available. It's hard to tell under a shaded condition, but if you take it out into the sunlight, and it reminds you of "Robin Hood" green, you should be fine... :)

As a general rule, Wool for outer garments, linen for underwear.
The kingsmirror, midt 13th cent., states that no man should walk around in linnen, and that you should make your underwear in such a fashion that it does not show.
This can be interpented as the medevial equalient of "thou shalt not wear a T-shirt at Work". In hot weather people would still walk around in their linnens. But they would only be "half dressed".

If you are making a 13th-14th century costume, it should consist of:
Tunic, Wool
Hose, Wool (Or, alternately, black leather. :D )
Shirt, linnen
Braie/drawers, linnen
+Shoes.