i think white's an easy color to match since that and black matches with everything. it might just be me, but i like doing simple looks that aren't too harsh for special occasions such as graduations. you want to be able to look back and say "i love how i did my makeup!", but actually, you can say that with makeup looks that you already like. i like the idea of wearing your school colors, but it wouldn't be a good idea if your school colors aren't ones that matches well. ok, so it might just be me, but i'd go with a brown eyed look. i can't see from you avatar, but i'd say that brown eyeshadows go well with all eye colors. my favorite these days are ricepaper, shroom, mulch, satin taupe, and twinks. also, bobbi brown makes some great eyeshadows, i just placed a huge order from them, but i've tried their shadows before. i have to say, check out black plum! okay, so it's not brown, but it's a great color! after all the shadow colors, don't forget to line your eyes, curl your lashes and pump up on the mascara!
go with a nice light pink blush that'll just give you the pinched cheeks look. i LOVE smashbox's o-glow! it's a clear gel that reacts with your skin chemistry to turn your cheeks to the color you would blush naturally. it's a great new product that lasts all day and best of all, it's packed full of antioxidants and other skin benefiting nutrients. one tip, wash your hands immediately after applying this as it will color your fingers as well. start with a little dab since it a little bit goes a long way, plus you can add more if you need to. i also like to add some kind of radiance, i love bare escentuals' radiances for this. for this, clear radiance, bare radiance or pure radiance would be perfect! to me, it's a miracle powder in a jar. it doesn't add sparkles to your cheeks, but just a glow. it's kinda hard to describe, but i love it. i don't know any mac products that would resemble the bare escentuals' radiance, since i'm not familiar with their face products.
also, i don't think wearing shimmery foundation would be recommended. if you have oily skin, the added sparkle will just be too much. keep it matte, simple and lovely! if you take pictures, you don't want your whole face looking oily or too shiny. don't forget to wear sunscreen, even if it's not sunny!
oh- don't forget to post your graduation photo and your makeup look! it would be nice to see the end results. hope you get more help from other lovely ladies. good luck and happy graduation!