blue mew is a shiny version of mew so you have to be very lucky to catch a shiny Pokemon let alone a shiny mew
Mew was originally found in Pokemon red and blue by using the Mew glitch.
In the game
Mew was a special event Pokemon that was distributed for Pokemon Red and Blue. Mew cannot be found in the wild without cheats or using glitches, which is still possible to obtain. Bulbapedia likely have a great summary about this Mew glitch in Pokemon Red and Blue.
The Pokemon that are in Pokemon blue are at least the first 149 Pokemon in the pokedex. I'm not sure about Mewtwo or Mew though
Mew i think i have a shiny one its blue :D
(Action replay) You can also use the Mew glitch in Pokemon red or blue and then just trade up.
The only way to get Mew in Pokemon Red, Blue, and Yellow is via the Mew Glitch, which you can find on Bulbapedia.
Anything.
It can be caught in Pokemon blue/red/ and yellow.
you didn´t get mew qith any cheats in ruby =( you can get mew with an mew-glitch in yellow (blue,red) or you can get a mew from my Pokemon ranch for diamant perl and platin but not for ruby the way to get mew in ruby is ... on a Pokemon tour (Pokemon-day ... , ) or with an cheat ... i hope i can help you :-)
Youtube video: "Catching Mew in Pokemon Red and Blue Versions" http://www.youtube.com/watch?v=JkF7Xjxn9jc
Zapdos Articuno Moltres Mewtwo Mew