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For future reference do the following: As your logo is black the the easiest way is to change Mode ---- Greyscale, then go ---- Dutone, in the preview dialogue box click on the Black colour then...

I can think of about 5 or 6 ways to do this. Here is one tutorial which explains some of the ways: http://digital-photography-school.com/changing-color-in-photoshop
Hope this helps or do a Google...