Brown and blue are normally for live and neutral on a mains AC powered device.
Red and black will normally be for a low voltage DC device.
So my first question is have you bought a suitable pump, is it a DC pump of the correct voltage and will the solar panals be enough to drive it.
If you do have the correct pump, then red to brown & black to blue seems the most likely, but if it is wrong the only thing that will happen is the pump will go backwards.