I know these are nonstandard, but looking at a fleet of all gray battlecruisers didn't appeal to me. I have built several 1/2400 wet navy warships from the WWII era and I am fascinated by the "dazzle paint" schemes that were used by various navies around the world. While people argue about their effectiveness, they make great subjects for war gaming miniatures.
So, I applied some of the ideas to my Klingon Deep Space Fleet. I decided that up to about the time of the General War, most ships wore simple gray schemes. Also, the standard model of any ship would be similarly painted.
Some of these minis are quite old and have been painted and touched up several times. A few have been moved, dropped, and repaired with varying degrees of skill.
Please, don't judge too harshly.
A C7, a D6, and an F5 (all basic models)


Exploration ships look the same, but have a light gray underside. Diplomatic ships have an oversized trefoil.
Here is the D7N Tyrant.
Even before the General War started, a few ships were painted differently. Command ships (also dreadnoughts, leaders, and command cruisers [also the B10]) have a gray/gray camo scheme. I might also vary the size of the "splotches" to differentiate a C8 from a C9.
Here we see a B10, a C8, a D7C, and an F5C.



Other ships use the camo scheme, too. Check out the D6PFT (Blue/Gray camo), a D6J (Tan/Gray camo), a D5G and an F5G(Green/Green camo).


Later, more ships were painted in various schemes. Carriers got swirly stripes in light gray. Thicker stripes might mean the higher number (a C9 vs. a C8, or a D7 vs. a D6, but I am not sure yet.) Here is a C8V and an F5V.

Check out my D6Y semi carrier!

Escorts have light gray stripes on the "wings" while raiders such as the C5 have black stripes. The tiny E5 has three stripes on the neck as those on the body did not show up at all. (I do not have a raider example as I don't yet own a C5 mini.) Here we see an AD5/D5E, the AD6/D6E, and an F5E.


The schemes got wilder as the war dragged on. Space control ships often use both PFs and fighters, so both schemes are applied to these ships. The scheme was also applied to other ships in the "Control Ship" series. The blue splotches are applied OVER the carrier swirly stripes.
Here we see a C7S.
Minesweepers have a geometric black scheme over the basic gray, while fast ships incorporate blue into the scheme. Here is a D5M.
ISF ships are solid blue, except for the flagship, which (being a leader) uses a blue/blue camo scheme. Here is IKV Regulator.
Drone ships have thick, jagged stripes of blue and black. Here are some examples a D6D (with special sensors) and an F5D.


By the end of the war, anything was possible. Scouts have thin jagged stripes of black and light gray applied over the darker gray. Also note that the placement of the sensor dishes varies, representing changes and experiments made over the years. Here is a D6S.

Supply ships have jagged black and dark blue stripes with light blue highlights along the blue stripes. Supply ships include the carrier resupply ships, military transports (freighters), LTTs, and tugs. Tugs are classed as transports no matter what type of pod they are carrying. Pods are not painted according to type. (They are all standard gray.)
Here we see a tug and a D5H.

The special weapons division handles maulers, stasis field ships, foreign ships in Klingon service, and any other special things I can come up with. They use a grid painted over the basic gray. This grid need not be perfect nor do any of the lines need to be parallel, equidistant, or even straight. Maulers use a light gray grid while stasis ships and foreign ships (RKLs) use a black grid.
Here we see a C7A, a D7A, a D6M, and an RKL.



My personal C7 (IKV Mirror, named for the ship from The Final Reflection) has a modified special weapons scheme. Here she poses with the captured destroyer Three Fingers.

I don't require that a player use these alternate schemes when they use my ships. I'll allow an opponent to have a squadron of "hot rod" D6s if they want, but if a special ship is in use, I do ask that the special scheme used for that type of ship not be used to represent a different type of ship.