Shinano was wearing Type 2 camo green at the time of her loss. It surprisingly looks alot like WW2 US Interior Green .
White Ensign Models does both shades in their Colorcoat line of paints, and I think the other companies do as well, Testors and PollyScale.
Japanese ships wore two basic colors, green (on carriers) and various shades of gray, depending on what yard they received their last paint job in. The colors are named for the yards, Sasebo Gray, Kure Gray, Yokouska Gray and Maizuru Gray. All are very close in tonality, so no one will correct you if you're not perfect, especially after weathering, etc.
Jeff