I have seen rocker panels that have had a texture to them to hide rock chips and other imperfections in the panel.  It looks like it was sprayed on then painted with the body color.  What kind of paint is this?  Is it tintable, or is it just a textured base coat?  

While I don't know about textured paint I do know that many people use a bedlining material like Rhino Lining or LineX, Herculiner ect. I know that the Rhino you can get in different colors but I don't know about the others. The rhino and LineX are sprayed on while the Herculiner(and other varieties that you can pick up at the local parts store and DIY) are brushed on.  

3M and SEM and others have waterbase or solvent based textures or chipgaurd type products and some are tintable.Some are sprayed thru a gun designed for this kind of product or rattle can,some are sprayed over the vehicles finish and some are prior to painting.Go to a auto paint store get what your needs are,keep us posted if any more questions.      WIEDER