You need four distinctly different colors: a.) lower hull which I think was actually an anti-fouling compound, not paint a medium but not too dark grey: I used Tamiya Neutral Grey, b. topside hull and conning tower (I used IJN grey but it probably has too much of a tan tint), c.) interior of conning tower, etc. (Tamiya dark grey); d. special preservative compound for wooden decking: Tamiya dark grey but with a mixture of Flat Brown, then drybrushed with Light Grey. It should look distinctly different from the plain Dark Grey. Note:despite some colored drawings and models you may see, the lower hull was NEVER painted red and the deck was NEVER left in bare untreated wood.