Here is my 1/48 Academy Su-27 that I finished in the Chinese PLA markings using Hi-Decal Line decal sheet #48003 for the SU-27 Flanker B.

Hi Decals are made in Poland, and it is as a whole a well done set of decals for the markings of the Su-27.  With the recent incident between the Chinese Air Force and the U.S. Navy EP-3, it may be of interest to the ARC readers that the Su-27 I made is a plane that came from the same Chinese Island (Hainan Island) as the ill-fated Chinese Interceptor that was lost after the collision with the EP-3.  I chose to do my model without some of the red dotted lines in the forward upper surface of the wing root areas as these weren't visible in the photo I have of this plane, but his could be due to the plane being repainted without these markings.  So always check your reference photos.

An example of 2 Chinese PLA Planes, click on above images to see larger images

As you can see in the above photos and also in the same blown-up photos to the right....the Chinese PLA uses different sized fonts for the numbers on their vertical stabilizers.  The number 38 scales up to roughly 400 mm wide in 1/1 scale.  I say roughly, because I was holding my caliper up to my computer screen to these photos, so my measurements are not 100% accurate.  The number 27 scales up to roughly 322mm in 1/1 scale.  The number 24 on the Hi-Decal Line sheet scales up to roughly 422 mm in 1/1 scale.  I didn't have a photo of the number 24 on the vertical stabilizer of the full sized plane. But I did some calculations and noticed the decal of this number was too big as compared to the #27 (although it is very close in size to the #38 in the photo to the right).  To correct this, I cut each number for stabilizer on four parts and placed the part in the model slightly overlapping because I wanted my number to look like the #27 plane.  It's possible the Chinese Airforce used different sized fonts on different planes at different times and that there is no right or wrong on this matter.

And now about the colours I used on this model of mine.  

For the inside of the landing gear doors and airbrake door I painted them Cherry Red.  For painting the wheel disks I would recommend Dark Green FS 34108/34128.  The inside of the landing gear wells were painted the same colour as the bottom side of the fuselage FS 26473.

Click on image below to see larger image.

The rest of the plane was painted according to the painting instructions included with the Hi-Decal Line Decal sheet.

Click on pictures below to see larger images.

I painted the air brake well a yellow green colour, it is an antirust paint used in Russia.

(click on the image below to load the full size photo)