#121 Starmie
Pretty simple... I changed the color from annoying reddish-pink ring thing to steely gray.
#128 Tauros
Yucky green-yellow combo is yucky. I just eased up on the colorful colors so they wouldn't look "yucky" and more natural. (Ignore the green legs error)
#135 & 136 Jolteon & Flareon
Jolteon & Flareon. I mean, I like eeveelutions, but these are just terrible. Green doesn't fit into Jolteon and lighter colored flareon is no appeal to me. Jolteon I just changed to light blue, because color of real thunder is close to light blue (as far as what we can see) and I recolored Flareon to dark blue, because it looks much cooler that way IMO (Some might not like it, oh well)
#150 Mewtwo
I actually have no problem with current mewtwo shiny sprite despite its common color green. It's still pretty cool. But I just wanted to experiment with it to see the frightening outcome of White & Red... Not bad actually.
#242 Blissey
Current Shiny Blissey is just a lighter version of its real self. I thought light yellow would fit in because it's a really light color :D (It could've been green or blue, but I wouldn't think it would've fit as much)
#371, 372, 373 - Bagon Evo Line
Green simply does not fit into these guys at all.... I tried to experiment with Red & Black, and it worked perfectly imo. (Bagon's sprite is bit off though... I couldn't get rid of the white on the top)
#382 Kyogre
I don't like purple Kyogre, so I changed it to silvery color, to contrast with Gold Groudon (Which GF incidentally messed it up with unnecessary extra lime-yellow in Gen IV IMO)
#445 Garchomp
Current Shiny Garchomp is as pathetic as it can be. It's almost exact same hue as the original, just with slighter hint of darkness than normal garchomp. I wanted to change it dramatically from the jet-blue pre-evos with white (To resemble a bit more of real-life sharks), which worked out fantastically IMO.