Subtle and interesting shading can be created using inks. Unlike washes, they tend to more uniformly tint regions, rather than heavily pigmenting recesses at the expense of raised areas. Experimentation is recommended to achieve the results desired, the effort will prove worthwhile.

The Imperial Japanese Navy rarely used camouflage patterns. This CL Tenryu is base coated with a medium grey (CLR17 will work).
The deck on this ship is linoleum. Paint all the horizontal surfaces with a deep golden yellow. Touch up the vertical surfaces with the medium grey.
Chestnut ink, thinned about 1/1 with water is applied to the deck. Don’t worry if a bit flows down the side, it looks like rust.
Details painted: anchor chains and anchors are rust with drybrushed silver. Next, the model is blackwashed. Here a “transparent” black acrylic paint thinned 1/4 was used.
Drybrush with off-white sparingly and the details will leap out at you. A protective coating, like Testors brand “Dullcote” can then be applied.

The more small details you can find to accentuate, the more realistic your forces will be. Try painting the canvas where the guns enter the turrets. Don’t forget aerial recognition symbols.