ILI9341 Performance Improvements

Unfortunately not ... getPixel tries to achieve the color at the given coordinates x, y, while getBgColor()has no coordinates as parameters at all. The getPixelreturn value is always [255,255,255] not being aware of the selected color format.

I've looked through a dozen sources of different ILI9371drivers in the net - and compared to the implementation the code seems pretty correct. So it's not easy to analyze where the unuseable return values are from. I guess this might be a slightly wrong setting of the display mode, so it returns only the whitecolor.