setpixel() method ignoring blue color values?

I've been trying to use the setpixel() method on an image object, which then passes its data along to a jittermatrix object which saves the image as a bitmap. I've also tried saving the image as a jpeg. For whatever reason the setpixel method keeps ignoring my blue values and is only using the red and green values. What could be wrong? I've tried having the js object print out the blue value, and it's doing that fine.