Most schematics won't even have any colors listed... so let us have you try this:
Find a system ground someplace like the sleeve of a 1/4 inch jack... Using an ohmmeter check for continuity to the available wires that are disconnected. ASSUME that those showing a low resistance will go to the "-" terminals of the drivers. If you have say a black and red... expect that the black will be one of the grounds... often the red then will be the (+) of the woofer. If you have whites and yellow... OFten the white will also have continuity to ground and be the (-) for the tweeter and the yellow then to the (+). Now since your speaker has 4 woofers we need to be careful to wire then correctly to get the 4 ohm impedance of the cab. IF each woofer is 4 ohms impedance, then we need to wire them in series-parallel. The shell of input 1.4 inch jack will likely go to black wires... two of the speakers will have their (-) terminals connected to these. The tip of the 1/4 inch jack will probably connect to one or more red wires. These will connect to the (+) terminals of the OTHER TWO woofers. Next one of the available (-) with no connections will tie to the (+) terminal of one of the first two woofers. SImilarly the remaining (-) terminal of one of the woofers will tie to the last (+) terminal that is vacant. Note the + of the horn will tie probably to the High level pot and this will tie to the crossover someway.
Here is a site with general schematics.