The white wire after viewing the image is the Positive (+) lead and the blue the negative (-) lead.
How are the connections labelled on the speakers ? I have found some speakers to have RCA connections, others miniature telephone-jacks, some have screw connections marked + and - and others have small pressfits. that is you have to press down or up to open the connection point, insert the lead and then release it and they are mostly Red for positive and Black for negative. So please say regarding the speakers and amplifier , which one is yours ?