For Atlas machines that were sold as Craftsman, Krylon Regal Blue is a close but not perfect match.
Original Atlas machinery was a a dark gray but I have not heard of an exact match being made yet.
For Craftsman/Walker-Turner 12" bandsaw, another close but not perfect match is Benjamin Moore UTILAC High Gloss Metal and Wood Enamel - Classic Navy #490 36.
Scott Andrew added:
I recently restored a 1937-1940 Craftsman 6" Jointer. I spent considerable time to match the original color before stripping the machine to bare metal. I used Benjamin Moore latex metal paint in low-luster as the base coat, and high-gloss for the top coat. This jointer was manufactured by Walker-Turner.
Base coat Benjamin Moore ~IronClad Latex Low Luster Metal & Wood Enamel
Quart Ultra Base 363 4B BK - 12 BB - 1x6 MA - 9 WH - 10
Top coat Benjamin Moore Impervex Latex High Gloss Metal & Wood Enamel
Quart Ultra Base 309 4B BB - 16+1/4 GY - 2x3+1/4 MA - 6+1/4 WH - 5.5
I have a Craftsman Drill Press 103.0305, Valspar #65031 Royal Blue was a very close match to the blue I found under the hinge.
For light blue Craftsman Table Saws I've found the Rustoleum Satin Wildflower Blue to be closest.
Brian Kachadurian added:
Sears blue: NOW (Sherwin-Williams) 21207 Royal Blue spray paint (ACE Hardware) is a good approximation.
Sears Power-Bronze: Rustoleum 261415 Champagne Mist metallic spay paint is a very good match.