I have some Pokemon that I think are Shiny in Red and Yellow. They might not have the sparkle, but they do have a different tinge to them (if that is the right word.) I have a Spearow and a Tangela.
I don't know, id have to see them. I don't Believe there were shiny pokemon till gen. 2. Since pidgey is purplish in red, im guessing that they just coudnt get the colour right.