The dotted lines that represent the radio, imagine that to be the end of the harness connector.......now you attach your harness adapter......are the wires from the adapter the same color corresponding to the wires of the original harness?
It really makes no difference.....you just have to follow the wires that come out of the adapter and while reading the schematic....
for example, the original harness is numbered and has an "A" or "B" row.....B1 is an orange colored wire, and it is the "BAT" power into the radio.....now it makes no difference what color the wire coming out of the adapter is, you just need to know that it is the power source for your new radio......now you have to find which wire(could be any color, usually red) on your new radio is the power input, by looking at the new radio's schematic, and attach this wire to it......your new radio probably only has one ground.....take the new radio's ground wire from schematic and attach it to either "A12 "(blk/wt) or "B5"(blk).....you have to do this for every corresponding new wire from the radio to the wires on the harness adapter......there are some wires that won't have attachments, like "A6" and "A7", which is for steering wheel controls(chances are your Alero doesn't have the option).......another one not used is "A1" Class II serial data, since this new radio is not a GM radio......
So recheck your wires one at a time.....