grays & black -> color

[Nikolai Vladychevski]

Hello,

I am trying to find out how to convert gray colors including black into
for example red color but have no success. I know I can select with
fuzzy selection tool but the problem is, I have a black shape and gray
areas that are used as antialising, so I want to convert it all like it
does Hue/Saturation but, Hue/Saturation does not works on Black and Gray
colors, why is this?

Thanks in advance
Nikolai