This one has been on the shelf so long, I can't remember which kit it is, but I like it in the MiG collection.
The Mikoyan-Gurevich MiG-9 (Russian: Микоян и Гуревич МиГ-9, was the first turbojet fighter developed by Mikoyan-Gurevich in the years immediately after World War II. It used reverse-engineered German BMW 003 engines. Categorized as a first generation jet fighter, it was moderately successful, but suffered from persistent problems with engine flameouts when firing its guns at high altitudes due to gun gas ingestion.
Yes, an overall grey is correct for this aircraft.