How noticeable would it be if my foundation is too light for my skin tone?

very noticable..u can try mixing the light shade with a dark one..but then again why buy a right shade and get it over with!that z why people shudn't buy makeup as a gift!at least includin' a reciept wud ve been thoughtful..but the point now is u shudn' wear an obviously wrong shade!this will do u no good dear!