I am using Pratt & Lambert floor paint for an outdoor (but protected) porch floor. The directions indicate that no primer is needed and, in fact, that using primer diminishes how well the paint adheres to the floor. My problem is that the floor appears to absorb the darker pigments of the paint, leaving me with a MUCH lighter color than desired. I have already had the paint modified with darker pigments but with very limited success. The floor is old oak (I hear groaning now), which I've scraped and otherwise prepared. So, can I use primer? Or is there another solution?

Many thanks.