Here's a blog that describes the allegations against the producers and the screenwriters:
colorrangers.blogspot.de
red - Native American
black - African American
yellow - Asian American
pink - female
[blue - Jewish?]
[green - Irish?]
Particularly the description of the blue Ranger is, let's just say, interesting and bold...
College Humor also took up this issue some time ago:
https://youtu.be/mJgC9LEBTuQ
It is very interesting now that you mention it, although Tommy's character is casted as being part "Native American". Especially in the earlier seasons I thought he could be mistaken for a "Black Irish" type. The color analogy would be undoubtly hilarious in that instance, given that Tommy later becomes "the White Ranger", and thus better and cooler than the "other" Rangers.