Yamato wore Kure Grey...the IJN had several shades of gray paint, all of which were basically similar (in that they're dark) but the differences were noticable. Typically, the ship wore the color of whatever dockyard its last refit was in...Sasebo, Kure, Maizuru, or Yokosuka. The hull red is a touch too dark, but not much...IJN anti-fouling red was very dark when compared to USN oxide red.
If you're airbrushing, the Model Master paint is okay, but if you're really going after this project heavy, take the extra time and order the IJN colors from White Ensign Models, they have perfect matches to the colors, and they're paints are enamels of Humbrol quality.
Jeff