I am slightly surprised that they didn't - especially with the newer ones where they have gone to the effort to change the furniture/signs/figures. The western sets do have a dark red roof now. But I think some different colours would have been good.
It would have been a 3 fold good decision to make slight color variations
1- maintains the collectors value
2- entices the collectors to buy the new variant
3- I forgot #3…..
It’s just looks good in dioramas, repurposes older molds and they could have marketed it as “Classic playmo”
Too early in California….tea time