I have never had trouble getting dark naturally, but I never go tanning or expose myself to tons of sunlight on purpose either.
I tried this at one point just because I like to experiment with things, and I got dark as hell without going to a tanning booth or laying out..... just working outside normally.
I did not like how dark it made my tiny moles/freckles that were barely noticeable before. I think some of them are permanent now, will not use again for that reason.