http://www.originalcolorchips.com/
My dad and I used this on his new 1000 sq ft garage and it has held up great over the past 5 years. The key is prep, prep, prep. Hopefully they haven't put a sealant on your concrete yet.
I am doing my in the next couple of weeks, but my garage floor is 40 years old. So I will be renting a diamond bit grinder to prep the surface.
I hope this helps.