Which color puts the least "strain" on an LCD pixel to avoid burn-in/ghosting?
I don't think any one color will be more "easy" on your display.  The circuit and structure for a LCD monitor are the same for each color, they just have a color filter in front of them.  There are other ways to do it with color changing backlights or color wheels, but that doesn't change the advice that the color doesn't matter.



--Edit @Trevor made me look up what the dominant behavior of LCD screens is and I didn't find a definitive answer.  "It depends on the resting state of the LCD as to whether they require energy to stop light or to allow light to pass through," was one quote I read on Scientific American's website. What I was trying to say before was it depends on the construction of your LCD as to whether the no power state is black or white.  You'd want to consult your datasheet or the manufacturer to find that piece of information and then put it in the off state for your particular device.