This review is for the Colorstay "stay natural" foundation, which is different from the Colorstay foundations for different skin types. I'm not sure how different it is, but they are separate products.
This is a great foundation. For background, I apply it with my fingers, without any primer (I know. I'm lazy and life is short). It goes on smoothly, light to medium coverage, pretty buildable. The texture is...foundation-y when you look close, I'm not sure how else to describe it. It evens out my skin really nicely and despite the SPF 15, it doesn't look shiny! At all! And it stays that way! I have normal-slightly oily skin and it keeps me matte! I don't know why, but I love that about it. I even went to the gym and it didn't slide off or get shiny. Another thing to love: it doesn't oxidise! When it dries, it does dry to a shade darker, which is fine for me since the colour I have is on the light side for me. It just looks so darn good.
smooths out my skin
looks good with light coverage
can be applied with fingers
doesn't slide off, resists sweat
texture might not be smooth enough for some? that's literally it.
EDIT: I got it on sale for $20, when it's normally $30. I wouldn't have tried it at that price but since it's so good, I'll definitely repurchase even at full price.
Also, I have olive skin, and a lot of foundations look super orange on me - this foundation suits my skin!! I'm so happy!