Black:
Replacement Black Grips for your ST3 to keep it looking and functioning as it should.
Red:
Deck your child's ST3 out in all this juicy red goodness.  Nice combo with a Green or Red ST3!  Increase visibility for a safer ride!  
Orange:
So you want to customize your Strider, huh?  Well, Orange is zesty and bold.  The ultimate here would be a gloriously orange bike... orange tires, seat, body AND grips.  Compliment that with your child dressed in orange with an orange helmet and you have a glorified traffic cone!  Talk about safe!  
Yellow:
A nice addition to your Strider, not only to enhance the look but also to increase visibility for a safer ride.
Green:
A Lime Green ST3 is tight, add custom grips to make it even tighter!
Blue:
Blue Blue Blue, Shoo Bee Doo Bee Doo! Blue custom grips for your Strider too.
Pink:
What makes a little lady feel more like a little lady?  More pink obviously! Custom grips to make things even pinker.
White:
Black, White, what a sight, make it bright and customized!