The colour can be patchy if applied too slowly, and very faint if applied strictly according to the instructions. Moreover, any colour effect achieved certainly doesn't last any longer than 48 hours, at least not on my skin, even though I cleanse gently with micellar water rather than using a foaming wash.
The instructions require that no moisturiser or liquid makeup be applied until at least two hours following application; that's a tough one for me as my skin is dry and hates to be without moisturising cream. Moreover, the tan application itself is somewhat unpleasant as one cannot avoid inhaling the steamed product.
Having tried every which way to like this product, I finally hit upon a reasonable compromise. I use a fine layer of hyaluronic acid serum ahead of the spray tan, then apply three layers at five-minute intervals. I find the 'Luxury Dark' tan works best in terms of colour - even on my pale complexion. I don't always wait two hours before applying moisturiser because I can't work that level of time delay into my daily regime.
My overall feeling is that, while this device is a clever and innovative idea, it's not quite ready to leave the drawing board just yet.