Rosie, please go back to the store and return your purchase! Most drugstores expect you to bring them back if they don't work and are okay with it.
it sounds like you got a powder with ashen tones. Since we don't know anything about your skin tones and coloration, or your skin type (dry, oily, whatever), it is hard to advise you more specifically.
But please do return the dead-looking powder.

If you can find a Sephora you can try on powders before buying and even ask for samples for free of anything you like. Try the Bare Minerals or a powder by Clinique.
here is a sephora link that goes to their specials pages: Sephora You can also try things out at the Nordstrom's counters if there is one by you. Don't worry about bothering all the counter girls - that is what they are there for.
Try many different types and only buy the one you fall in love with.
If you really prefer drugstore brands, maybe someone else can advise you here? I don't like drugstore brands since i can't try them out first: i want to love what I buy, not merely 'like' it. otherwise it's a waste of money and sits in my drawers rotting.
