I believe yellow indicates near the edge of acceptable. The left may actually be say 3.98 and the right 4.02. Both would round to 4.0, but the right shows yellow. Close enough. The red camber is probably just the combined tolerances of the rear suspension. If the shop is motivated, they can loosen the bushing bolts and maybe get a few tenths. Otherwise, a camber kit (bolt) is in order, as the CROSS CAMBER (LEFT- RIGHT) is best less than 0.5 degrees.