well for porygon anything more colorfull is good( the current shiny is rly nothing to brag about). as for shiny empoleon you could add some red like u did for pikachu.i think it would make it look way more interesting. As for togekiss i dont really know maybe just change the basecollor to blue/aquamarine and fiddle a bit with the colors for the points/head. (like you did with sandslash that one looks really dank)
edit: shiny empoleon right now is basically a penguin.