Wrong. Blue (and White) LEDs are a relatively recent invention. I'm not
sure when they first came into existence, but it was WAY after 1991; it was
closer to or even after 2000, although it might have been in the very late
1990's. White LEDs were even later. There were 3 color LEDs in 1991, but
not RGB.
I bought a blue LED while I was doing my Ph.D. at Bristol (this would
therefore be before 1995). And that was from a hobbyist shop, in 1-off
quanities. It wouldn't suprise me that they were around a couple of years
before I got mine.
-tony