WOuld the CTC-5 be considered a "2nd or 3rd generation" color set??

[rca2000]

I am curious about something. The RCA ctc-5 is described in old magazines as the first "affordable color tv" set, and considered much simpler made, simpler to use and more reliable the those that came before. Perhaps that is true....it is certainly simpler than a CTC2, either with the 15" or the 21" version. But would it be considered a newer generation than the CTC-4? if so, it would be considered a '3rd. gen" set. Or--does it belong to the same gen. as the CTC-4, making it a "2nd gen. set?