Taking a brand new car to a paint shop right of the lot doesn’t seem mighty efficient.

The premium manufacturers usually offer colors other than neutrals at a premium, and what the OP is pointing at is that economy brands don’t offer that option at all. Why can’t we have both cheap neutrals and color options?

> Why can’t we have both cheap neutrals and color options?

No one wants to bear the extra costs for color lovers. Dealers don't want to be stuck with the banana-yellow cars for months on end, and manufactures don't want to switch their painting booth paints for colors that are <1% sales when they can crank out 5 more white cars in the time it takes to switch colors.

Wraps are cheaper alternative to repainting, so those who love bright colors can get an electric blue wrap right off the parking lot.

It might be less efficient for the few consumers who do want custom colors, but it is by far more efficient for the rest of consumers and the company to limit their color choices. Their manufacturing processes aren't set up to do very small runs of specific colors, and for those premium brands that do offer custom colors, the further away from the standard offering you go, the more you pay. Custom colors on some of the premium brands can easily run into the thousands of dollars, largely because they're doing effectively what I suggested -- doing a custom paint job towards the end or after assembly.

Not to mention that even supporting the pipeline of being able to order custom colors, with all the logistics that entails after manufacture, might not be something the manufacturers want to support.