Restaining concrete?
 

My concrete patio used to be a mottled red-brown, to match the adjoining flagstone. After 15 years of sun and pressure washing, most of the color is gone. Who knows about restaining concrete. Is it a DIY job?

Try the copperous method. Really works.
https://www.google.com/search?q=copperous+stain+concrete&ie=utf-8&oe=utf-8

We've talked about staining our back patio, but it's so slick when wet. Need to find something to make it less slick not more!

Add Gatorgrip to sealer. http://www.amazon.com/BonWay-32-541-Resistant-Additive-Gallons/dp/B000CODWBS

The copperous method doesn't need to be sealed.

So this is a DIY job? I don't want or need perfection. The patio looked rustic before, rustic again is fine, just not glaring white.

It's actually really easy. You basically dissolve copperous, which is a fertilizer you can buy bulk, in hot water and mop it on. You can use more for darker or mop it multiple times.
You probably already have some stains on your sidewalks from fertilizer that is the same thing.

Park your 911 on it.
Might not be the colour you are looking for though...

I don't get too involve with concrete staining myself, when it comes up, I call in my experts or sub contractors. That said, I have done some minor staining over the years. OSH carries premixed concrete stains and it works pretty well. Clean or etch it really well, stain, and seal it. Depending on the condition of the existing surface of course. The catch is that you are limited to colors off the shelves.