Try doing a search for Masons Select. They have a good website with some nice examples. They used to have little cans they would give out for people to try, I've used a number of their stains and liked them.
Cindy

Concrete Depot in Shawnee Ok is where I got my samples from. Tried 2 so far. Nice looks.
Paws

That's a great site. Sample prices are reasonable.
Thanks, Paws
Rhonda

I just spent an interesting afternoon following up on these leads. It turns out that the "Concrete Depot" in my town has nothing to do with the Oklahoma store. I did find the online site for the Concrete Depot and I plan to order their sample kit - Thanks, Paws!

Cindy - I found the Masons Select site and it mentioned that any authorized dealer will have FREE sample cans of the concrete stains. My town had 2 authorized dealers listed and I phoned each and was told various versions of "lady, you are crazy". The second store - when I read them the online statement - had the courtesy to say they would call their supplier. I got a return call in 30 minutes saying "oh yeah... that's what is in that sack back in the storeroom". I just now drove to that store and organized the sack for them. Turns out they also had free samples of wood stains for decks in there. Of course the 2 colors I was most interested in were not in the sack, but I brought home 5 free color samples of the masons select transparent concrete stains. They are about the size of tuna cans and have handy pull-top lids.

When I get time I am dropping by the other authorized dealer and suggesting they look for their grocery bag full of samples!!

so - fellow concreters.... there may be free samples available in your town too. Happy hunting!
Laura

Laura-I was away,so I'll throw in my late 2 cents worth.I've used DAVIS Colours for 4 years now.No problems of any sort,and I use some MASON Powders as well that I got from my silica supplier(pottery store).
The DAVIS are in 1lb bags minimum so samples might be a problem,unless you want to share with a nearby 'creter.I bought larger bags before leaving the city(2 plus years ago),and I've still got lots left.I read their website and their literature and I don't go over 5% by weight of the cement.I stuck with black,brown,terra cotta,palomino and green.Tried blue in MASON,not bad.For other colours,I'll try the tinting thing,or different finishes.I'm interested in what you get as results with the stains as well.
Cheers from "Oh,My God!It's so freakin' HOT"here

'Concrete Chemicals' aka Liquiblack sells concrete colors for swimming pools (although they have branched out to countertops). They'll sell to hobbyists as well as professionals.

Here is a link that might be useful: Integral Concrete Color