Outer Limits 4x4 Board

Hi can anyone help me,
does anyone know what wire i would need to use to connect a speedo correction kit from jcar? Is there a wire behind the dash that i can use or do i go from the gbox? what are the colours?

pretty sure the speedo sender wire is the green wire mate, the black wire with it is an earth.

thats in a gq tho i think u have a GU by your sig