Though the Getty Center in Los Angeles has been rightly described as a masterpiece, it is coming up a tad short in the amenities department. Already reported has been its lack of bathrooms -— wags have suggested that when visitors call to reserve parking spaces at the museum, they should also be permitted to make reservations for one of the few rest rooms -— but there are other problems as well. On sunny days the brightness of the light on the mountaintop location is exacerbated by the reflection from architect Richard Meier’s tan aluminum panels on the outside of the building. Employees now wear dark sunglasses as part of their work uniform. After the December opening -— coincidentally, after Meier left —- umbrellas were set up to provide some relief on the virtually shadeless plaza. But the glare isn’t all. During the winter, visitors were slipping into the lovely rain-swollen pools because they couldn’t distinguish where the travertine ground ended and the water began. And while the violations have been corrected, the Health Department initially graded two of the Getty restaurants a mere C.