I don't even know what color adding does...
but color isn't texture you know...
go into your Geanocise folder in the shipped assets.... and open up it's world folder... browse the TGAs in there till you find nice dirt/ground texture and copy it...
place it into YOUR map's world folder and rename it to floor.tga
then open zero edit, select textures, and in the bottom left there is a empty field... type in floor.tga and press enter... this sets your texture #1 to your floor texture.... then just paint your textures
there...
