Did you ever wonder what colors your dog perceives? If you haven't, don't worry, because other people have.
She isn't blind to all colors, she just doesn't see red and greens like her master. But she sees blues and yellows pretty well.
The picture at left is a composite. On the left is a picture that I took out in a mid-western corn field, while out walking Blader dog. On the right is the same piece of corn but the picture was taken by Blader dog, after I got her to sit still for a while and focus on the task at hand.* It is almost like you can't really blame Blader dog for acting like she thinks she is on another planet.
If you don't have a dog who can be trained to take dog-view pictures for you, then you can use color blindness simulators to achieve a similar effect.
*warning: do not attempt this trick with shepherds, pointers, poodles, spaniels or especially terriers and mixed-breeds thereof.