Since the beginning of the beauty industry, makeup for white women has been easy to obtain. Think about it, you (a white woman) want a new cover up or foundation. All you have to do is go into the cosmetics section of your local drugstore. The only issues you might have would relate to finding your correct undertone, and you think that's hard. Imagine being a woman of color, going to a drugstore in hopes of finding the right color and being extremely disappointed when you find out your skin tone is "too dark". In my opinion no skin tones are too dark or too light, we were born as we were and there should be no issue with the color we were born as.
The problem here is simply that drug store brands don't extend their horizons, they cover one maybe two of the darker skin tones. I wouldn't know from personal experience (because I am white), but it can be assumed that finding the right foundation color as a colored woman is bothersome. A way to see this struggle is through this Buzzfeed video where it shows three women going into the drugstore and buying foundation. You see the actual struggle when one of the darkest shades offered was "creamy beige".
Women of Color Try Drugstore Foundation
Because of this issue, many darker skin women go to places like Ulta and Sephora to buy more expensive brands as opposed to the well known brands like Maybelline, Covergirl, Lo'real, etc. But even when women of color go to expensive beauty shops, the color isn't always true to the skin tone. An example of that struggle is shown in Nyma Tang's youtube videos. She posts multiple videos of her trying the darkest foundation shades of each brands makeup and compares them to her skin tone.
NARS ALL DAY LUMINOUS vs LANCÔME TEINT IDOLE (the hyperlink should lead to directly to the time of 2:12 to show the difference between the two darkest shades).
The real reason Rihanna's makeup line "Fenty Beauty" is such a huge hit, is because the foundation comes in forty shades. The shades range from very fair skin with neutral undertones to very deep skin with cool undertones. Rihanna (as a woman of color herself) made her goal for Fenty to utilize all skin tones in a natural looking foundation texture. The fact that Fenty was launched with so many different shades is a big step for the beauty industry as a whole. Many companies don't even carry darker shades when they first launch because they know they'll make more sales from the typical beige female population as opposed to the significantly smaller colored population.
If I leave you with anything, I'd like to leave you with a question. Why is something as simple as foundation white privileged in society?