I tried the 4.5 first but it was just a tad too dark and to be honest this does have a somewhat yellow understand and I think the perfect shade would actually be to mix the 4.0 and 4.5, but I've gotten more compliments on my face and complexion with the 4.0 . I just dab some on top of my hand and with my sigma f80 and it applies so easily and is lightweight enough that I can highlight and contour over it. My only setback is I have an oily face and while this isn't oily when applying I find that throughout the day I have to go in with the UD naked finish powder to get the oil off my t-zone. I just need more coverage than a powder foundation, but I do love this product. And the only other small issue is that if this is your only foundation you might be in a pickle, b/c it's really hard to tell when you are about to run out.