Hi, John (@johnb). I probably know less than most, but blue-black has always seemed to be a really dark black. I haven't really noticed a distinct blue tone to it.

@lgardner, thanks a lot Louis.
This is wonderful information and will be very helpful during the build.
I can imagine that it is difficult to get exact matching colors because of all the fading which occured in those weather conditions. At least if you are going to build a 'used' aircraft.

Thanks guys for the references to available colors suitable to represent blue black. I have searched for a specific blue black paint and I haven't found one yet. And thanks for the education on the FS color numbers regarding flat, semi-gloss and gloss. Blue black is also useful as a base coat for WW2 German tank crewmen. Use straight black for shading.

Nice work, Spiros (@fiveten) and John (@johnb). I'm not much of an aficionado on colors needed, so I have been using AK Real Colors for my Japanese planes. I really like this line of paint, which works just like Tamiya paint, and they have a complete line of specific Japanese colors from WW2. The colors are identified by their Japanese name, but it is easy to find which color you need online. The colors are numbers 302-307, and 328-335. They include two different cockpit colors, one for Mitsubishi and one for Nakajima. Tamiya has also been coming out with colors that are specific to Japanese WW2 planes, both in their original line of paints and in their new line of lacquers. I am sure other paint lines have colors for Japanese planes, but I don't use them, so you are on your own with them. Good luck finding what you need.

I suspect the color will be fine, Spiros (@fiveten). There is so much variation in color that it is tough to pin the perfect color. Different factories and batches of paint are different. The stuff available to make the paint varied from early to late in the war. How the paint was applied made a difference. Then you start thinking about the environment of the war: sun, salt water, sand, etc. All make getting a specific color very difficult. You could probably use any color of shade of grey and make a case for it being correct. In the end, all that matters is if it looks right to you. :o)

@johnb, @gblair, @lgardner, @lis, @jaltergott6 , @fiveten (hopefully I have everyone). The planes are progressing nicely, I'm glad you two are having issue free builds.
Looks like I missed a lot since last I checked in. I echo George's comments, the AK RC Japanese paints are very nice and very convenient to have (I'm not much of a paint mixer guy) on hand. when I first received them, I had to to a bit of research on how exactly to use them, so I will save you all some grief and explain them below:

AK RC302 IJN J3 Hai Iro (grey): used on pre-war IJN planes and used on fabric control surfaces on IJN planes throughout the war. If factory green paint was applied to the plane then the upper surfaced of the control surfaces would be green.

AK RC303 IJN J3 SP (Amber Grey): a modified J3 paint used on Zeros, Vals, Kates (single colour camo) and undersides of Zeros, Vals, Kates, Raiden. I have yet to look at later IJN aircraft, but for the most part their undersides were bare metal (ie George, some Jills, Frances, etc). Nick Millman sad to cut this with 10% white to get the proper shade. Nakajima had a darker version early to mid war , but eventually they were the same (this may be contested as some say Nakajima's underside grey was greyer in the later part of the war like Mr Color C56... I need to look into this more).
AK RC304 IJN D1 Deep Green Black: Used on Nakajima built naval planes and most likely the Nakajima built Zero as well. I'm not sure if this was used on the Kate (either field painted or factory).
AK RC305 IJN D2 Green Black: Used by Mitsubishi on their naval planes as well as Vals and I think Judy, Rex and George (I need to review AoJ again to confirm this).
AK RC306 IJN M3 Mitsubishi Interior green
AK RC307 IJN M3 (N) Nakajima Interior green: I have yet to look into the interior colours of the D3A, D4Y, and N1K, but they are probably close to one of these two colours or a mix of both.

IJA Paints
AK RC 328 Hairyokushoku (grey green): if IJA plane was painted overall grey, it would be this colour. Ki-21 Ki-27, Ki-46, Ki-48, Ki-51, Ki-54, Ki-57. This colour is also sometimes called out for underside paint, like on the Ki-43 I, but I think this may be a mis-interpretation of black and white photos, as most IJA planes left the factory unpainted. Also used on fabric control surfaces. AKA IJA #1. May also be used to paint the interior of a factory unpainted Ki-61 (with a touch of Ral 7028)... do not use RLM 79

AK RC329 Hairanshoku (grey Indigo): pre-war to early war interior colour, used up to mid 1943. AKA IJA #3
AK RC330 Ohryoku Nana Go shoku (olive brown): also known as the Japanese version of olive drab. After mid 1944, all IJA planes were factory painted this colour inside and out (solid colour). Used on late war Ki-43/44/45/46/61/84/100, etc. I don't think I have seen a Ki-44 painted in this colour. AKA IJA #7

AK RC331 Midori Iro (green): used on Nakajima planes (but not exclusively) as topside green camo (field or factory applied), as on the Ki-43, 44, etc. Also used on field camo Ki-21 AKA IJA #21
AK RC332 Ao Midori Iro (blue green): used on Kawasaki aircraft Ki-45 and Ki-61 for field applied (Ki-61) and factory applied (Ki-45) camo. Not sure about the Ki-48, but it would make sense to have used it. AKA IJA #27
AK RC333 Ki Midori Iro (yellow Green): Mid war interior green 1943 to mid/late 1944 AKA IJA #29
AK RC334 Karekusa Iro (dry Grass colour): used on multi colour (green, brown, light brown, grey) camo planes (ie Ki-30, Ki-32) AKA IJA #30
AK RC335 Cha Kasshoku (tea colour): used on multi colour camo planes (similar to AK RC 334) AKA IJA # 31

There are additional paints that are Japanese specific that I use:

Mr. Color
C58: Orange yellow for leading edge stripes, may be used for trainers nut might need more orange
C125: Cowling color
C131: Propeller color
C327: FFS11136: I used it for Hinomaru or any red colour on Japanese planes
C383: Kawanishi Dark green: Paint was developed for the Hasegawa 1/32 N1K2 but as per Nick Millman it is too blue.
C384: Kawanishi Interior green
C385: Hinomaru red. Paint was developed for the Hasegawa 1/32 N1K2

AK
AK RC060: RAL 7028 I use this for Kawasaki interior colour 4:1 ratio with AK RC 058, but could be used on its own. can also add some to AK RC 329 to create a similar colour. Do not use RLM 79, too dark.

@lis
That's good to know, I will add it to my notes. Thanks

Just want to mention that those are the paints I use but those are not the only paints to use. As @lis mentioned, there are other Mr color paints that can be used: C15, 16, 35, 56, 124, 126, 127, 129, 130, their Aqueous equivalents and of course the Tamiya paints.

@wkubacki C56 don't match any IJN Color. This shade can be considered unsuccessful. From Mr Hobby Brand nice Hybryd of IJN Green is H59. If you remember I used it on my A6M2 from Oita school. But now I use C paint series. Very good Green is C129. I used this paint In one of my A6M5c.

PS. H36 Paint Nick described it as a very similar shade to the fragment of G4M sheet he has. I used it in the A6M5 Saburo Sakai.