The only extra work required by the ladders was a little bit of filler in the upper (white) part. It's a little hard to reach, so some thick craft type glue might be easier to 'clean up' after filling than honest to goodness putty.
As far as the white - every Prowler I've ever crawled up in the last 12 years had red lower and white upper ladders and I did a quick internet search to make sure the same was the case for the Intruder. Turns out it is, or at least enough showed up in the interwebs for me to feel comfortable doing it...