well you have a solid colour and the same colopur with a white/gray strip (orange for rear left... can't remember for the right)
i think the strip denotes the -ve terminal... but not sure.
If i remember there was a +ve and a -ve marked on the existing speaker...(not sure tho) just look at the wires to see which goes where from the wierd connecter block.
one way to check is to connect them to your new speakers and listen. one way round should sound quite good with plenty of bass and clear high end. The other way round should sound very 'mid', with the bass and the high end stuff not being as apparent.
Also if you watch the speaker when you play something. preferably with some bass thumps in it... if it's connected the right way round the speaker will 'throw'outward on the start of the note... if it's connected the other way round it will 'pull' inwards on the start of the note.
anyway that's just a rough guide.