What is the color layout for a a cross over cable?

Std. or straight-through Ethernet cable, by 568b specs, is Or/Wh, Or, Gr/Wh, Bl, Bl/Wh, Gr, Br/Wh,Br. Both ends.

Crossover is standard on one end, but Gr/Wh, Gr, Or/Wh, Bl, Bl/Wh, Or, Br/Wh, Br. You are crossing your transmit pair with your receive pair. Some sources would have you cross the other two pairs, as well, but it's not necessary.

Or = Orange, Wh = White, Bl = Blue, Gr = Green, Br = Brown.