Then too, I've seen Curb Appeal episodes where the old front porch was stained; even one where the front sidewalk was stained. Most stains that have a lot of colorant added look like paint because they do, in fact, have paint in the oily stain. I am thinking of Terra Cotta, Cedar Gray, etc.
A clear stain obviously wont do much to change the original concrete color.

When my patio was poured, I had colored 'crete. i.e. the color is thru and thru. One easy and inexpensive way to color your porch, say, is to add a thin layer of colored 'crete atop the old. Chips will show of course, but I imagine it will last longer than concrete paint.

I may experiment in the storage area of my basement just to see if I could get a nice color in old grey concrete. My front porch could use a fix up.
Pondy

Also, we have a concrete patio that I was thinking of painting a terra cotta color, as a quick, inexpensive way to make it look better. But that comment by pondwelr is making me wonder if it would be best to re-cover with a colored concrete. Is that a easy enough do-it-yourself project?

good luck, linda

tc~

Make sure you check out the photo gallery there's a slab with a geometric design that I want to copy someday.

here's a clip from www.acidstainconcrete.com

Add to that the fact that unlike others floor finishes, acid stain is translucent. Rather than covering the slab with color, it creates a chemical reaction that transforms the color of the concrete itself. It doesn’t cover up the imperfections in the slab, it accentuates them.

here are some links
http://www.decorative-concrete.net/stained.php
http://www.kemiko.com/
www.scofield.com
www.elitecrete.com
http://www.concrete-stains.com/
www.askthebuilder.com/219_Concrete_Stains.shtml
www.advancedsurfaces.com/