In GSC if you bred a shiny ditto with a pokemon it would be shiny. I'm not sure if breeding a shiny with a ditto will increase the chances of the egg being shiny. I don't think it will though.
Any egg can randomly be a shiny though.
IIRC, in GSC, shinyness was determined by IVs, so breeding with a shiny increased the chances (because of IV inheritance).
In 3rd gen and 4th gen, the chances of getting a shiny out of an egg, no matter what 2 pokemon you're breeding, are 1/8192.
_________________Need homework help? "Screw the Ivys, I'm applying to Smogon University!"ShiniesRuby:
Spinda, Golbat, DuskullPearl:
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