Not a fan of the stuff myself, its like black emulsion paint. Im not at all sure how good it would be at changing a colour, as its meant for re colouring whats there already, its pigment is not that strong.
blue to black with renovo very successfully, 6 years and counting! bits that rub when repeatly fitting the roof need touching up once a year (done when anually fabsil-ing for waterproofing),no probs. hope this helps.
