Yes Sir...... I dont know if its because i have two different monitors but when i use the eye dropper i will put the paint color that i am copying on my primary screen then click and hold the paint dropper and drag to the image. its kind of a pain always having to minimized Lumion but its what works for me.
Perhaps you should get another monitor Allen!
Or alternately, Right click a tab and add NEW HORIZONTAL (OR VERTICAL) TAB GROUP ... in one monitor so that you have multiple windows open in one monitor.