Display Detective provides useful information about the pixel under the mouse pointer no matter where it appears on an attached display. Specifically, it gives you the absolute mouse coordinates on the displays along with the RGB saturation percentage of the pixel color currently pointed to alongside the HSB (Hue Saturation and Brightness) values. The lower portion of the display shows you a color swatch to visually verify that you are pointing at the color that you are interested in.

This can be really handy for determining the exact color being used in an application for which you do not have the source code. It can also be very useful for determining the precise coordinates within a window, relative to the display, to calculate exact positions of elements being displayed.

In the sample screenshot below you can see Display Detective running at the top right corner of the screen, revealing the color at the mouse position (the red patch in the middle of the chip in the web page) and the absolute display coordinates of that point to be 832.20 pixels to the right of the left edge and 407.04 pixels down from the top edge!