I have spent hours over-thinking this very thing. I have agonized over paint sheens, colors, LRV, and base colors. I have learned a great deal in this process. One option would be to bring a scrap of your metal ceiling to Sherwin Williams which can color match your white. They can match it up so there is no guessing. I also like the idea of using one color but different sheens, Flat walls vs glossy metal in the same color would look great. That metal ceiling will need a trim piece. You might consider using a semi gloss on a trim piece in the same color then a flat on the sheetrock wall.
I found that it takes a super bright white to point out any type of meaningful off white to the naked eye. I did that in my shop build. The trim, beadboard, and ceiling are all semi-gloss "creamy" white. To make the contrast show up, I used a super bright white in a flat finish on an upper sheetrock wall. Without this bright white upper wall and bright white matte framing some artwork, the creamy/antique white would not be noticed. You also have to know what temp of lighting to use. I like warm white (not vintage yellow) but a normal, traditional white bulb color. My overheads are very bright LED's set at 4000 temp, but I rarely use them. most of the time I just use the LED cans set at about 3500 lumens. My door trim and cabinets are a very orange tinted antique white that I found by matching 100 year-old built in cabinets in this building. I suspect their warm/orange glow stems from the decaying lead paint. They really glow a warm orange under the warm lights, but turn pretty light tan when the super bright LED work lights are turned on.
Another trick I learned to consider is LRV = Light Reflective Value. Every paint color has one. Black would be a low number like 14 and off white would be a high number like 89.
The rule is simple and really works in real life.
If you choose two colors make sure they are at lease 30 LRV apart. For instance A machine gray of 40 LRV with a complementary lighter gray upper wall should be at least 70 LRV away from the 40 LRV. This also applies to different colors/hues. For instance a blue and a green side by side in the same LRV range will fight each other. However a darker blue with a 35 LRV paired with a light green of 65 LRV will look good together. It is a real magic trick once you learn it.
My big display area I am just now finishing uses
two other tricks: 1.) color drenching (all one color) using flat, semigloss and satin on the same wall with lots of different trim work.
Second the
"Three Color Rule" 1. a main color, 2. a major trim color, 3 and accent color. 1,2,3! The green walls, brown trim, and orange/brown doors illustrate this technique.
I love white walls in a garage. It seems to look clean, and not distract from the cars and other interesting things.
It really comes down to personal choice. Anything looks nice once it is painted. I prefer the more traditional white, greens, grays, that vintage machine shops and factories have used over the years. The reds, oranges, and other bright colors are too loud for my tastes, but again, anything clean and crisp looks nice.
