Interior colors had been done by Petra Scotese since issue #325. Not sure if she did the covers as well. Some time during this run she leaves and I believe it was stated she retired from comics. Have to find that letters page mention...
The coloring process around this time were really hit and miss. Not sure if it was the paper or whatever new process was being used, but in the upcoming Web of Spider-Man crossover, BLARGH! What a **** show!
***EDIT***
Found it in the letter column in issue #355. She didn't retire, she bought a boat and sailed the ocean for a while. Honestly do not know if she came back after that or not.