[JavaBrewer]

Most of the concrete stamp & color work I have seen is done after the concrete is poured. They throw various colors (powder) on the fresh concrete and then tamp in the pattern using large rubber mats. Personally I don't think the color will hold up on a driveway. I had multiple neighbors who did stamped and colored walkways and they needed to be sealed every year or so - and still never looked as good as the first year after install.

Concrete stain (acid) is much more reliable but can tend to fade with heavy use. It can be applied on new or old concrete. I did a stain on my poured-in-place BBQ island top and then went over it with a clear coat. Looked amazing for years.