Match color-to-color EXCEPT, like you say, switch the two power wires. You may do this by popping the connectors out of the Metra adapter so you wind up matched color-to-color, or just connect red to yellow and yellow to red.

Solid blue is the antenna wire on the headunit's harness. It should just connect to solid blue on the Metra adapter. Blue/white is amp turn-on. I don't remember off the top of my head whether the stock amp(s) need this turn-on signal (since my stock amps are sitting on a shelf somewhere) but if you get no sound, just connect blue/white to blue/white.

The code wire is left open, and the smaller harness is left open as well, as it's just all the wires for the telephone.

'95s are super straightforward, and you'll be rocking out in no time.

EDIT: As for actually doing the connections, solder and shrinkwrap is lovely, blue splice connectors with a GOOD set of crimpers works great too. I like to twist the two wires together, slip a splice connector over the twisted bundle, and then crimp the whole mess together. Half as many crimps to go wrong, and you wind up with a copper-to-copper connection.