The problem is you're more than like going to get more than one pixel that contains that color.... Like the windows task bar is the same color grey so if you match it then you will match all of the bottom pixels on your display. Anyway, to move your cursor to the first located pixel.
Why don't you tell me what you're really trying to do? Yes, there is a faster way. The way i'm doing it processes the *entire* image but it could be changed to stop after it matched the first pixel.
Locating screen pixels is not very accurate and i'm having a hard time envisioning what useful task you could be doing with this :)
Please elaborate