Are women allowed to colour their hair brown, using (colourwash)semi-permenant hair dyes? Is Wudhu/Namaz accepted if such dye is used? Wat about the alcohol content?

A woman is permitted to use brown hair dye provided the dye is permeable (water can pass through).

If the dye contains any Haraam ingredients, it should be avoided as other Halaal alternatives are available. Nonetheless, even if she uses a dye with Haraam ingredients, her Salaat will be valid if her hair is washed after application.

And Allah Ta'ala Knows Best