Here's what I used for ligting the Enterprise NCC-1701-A model:

-six white 4-inch 12V cold cathodes,
-two white 12-inch 12V cold cathodes.
-2 red LEDs
-15 yellow LEDs

I originally planned on putting 8 four-inch tubes into the saucer section, but ended using 4 six-inch cold cathodes for the saucer section, two six-inch cold cathodes for the secondary hull and 2 twelve-inch cold cathodes for the engines.
While cold cathodes do come in blue (and green, red and UV), I only used white ones.

On 8 and 10 o'clock, you can see the drivers for the four cold cathodes in the saucer section.
One driver can power up to two cathodes, so that saved some room.
On 3 o'clock, the two circuits for the blinking LEDs: one for the 4 fast blinking LEDS and one for the 9 slower ones.
Both circuits have potentiometers built in, allowing adjustment of the speed.
(accessible thru a hole in the saucer section, by removing the bridge which is attached by magnets.)

I used two red LEDs for the red lights above the shuttle bay, and two yellow LEDs for the positioning lights on the sides of the rear ends of the engine narcelles.

I did not put any white LEDs into the spotlights at the front of the engine narcelles. The light you see in the pictures of the finished model is from the white cold cathodes inside the engines.
The two red impulse engines at the back of the saucer section and the red photon ports under the saucer section are both lit by the cold cathodes inside the ship. So are the 16 rectengular positioning lights in the saucer section. I used red, brown, yellow and orange gels to get the desired colors.

The yellow masking tape you see in the picture above, is stuck on the magnets that hold the two saucer sections together. The tape is only temporary to weaken the magnets and making it easier to pull the saucer apart.
Once all the lighting has been installed, the tape will be removed and the magnets will hold the halves together with their full strength.

I decided to not glue the saucer section shut so I will still be able to replace broken LEDs or cold cathodes.
Cold cathodes last about 15.000 hours. LEDs, I believe, even longer. But I did not want to take any risks.

The longer (12-inch) cold cathodes in the warp drives, by the way, are each powered by one driver placed into the rear ends of the warp narcelles.

90% of the cables inside the ship are hidden behind aluminum foil.
The tin foil bounces the light around inside the ship, making the lighting brighter.

At the top of the aluminum tube, you can see the main power line supplying the 12 volts for the ship.

If you are building the same (or a similar kit) make sure to either paint the model black and then white from the inside or to add tin foil on the inside to keep light from shining thru the material that in certain areas is very thin and translucent.