Usually elastomeric paint can't be tinted as dark as normal house paint. How dark depends on the manufacture. Plus, there isn't another paint that even comes close to its elongation properties.
Pratt and Lambert Paints has a deep tone base for elastomeric. Also, I have used a ICI elastomeric that can be tinted to some dark colors. Just how deep can these can go? I don't know the full answer, but I have used them with some rather deep colors.
You should ask the painting contractor, 'What brand you are using' and get a color deck with the choices for an elastomeric. If you plan on doing the painting yourself, visit with your local paint stores. Talk to the lead salesperson and, if possible, request or purchase samples before application. (Most elastomeric paints are sold by the 5 gallon bucket and samples are not available.)