Hi Andy,
F-16Cs began in a three-tone camouflage, with FS 36375 on the lower surfaces, FS36270 on the lighter grey upper surfaces and FS36118 for the dark grey. That's 'factory' paint, which over time has become FS36118 and FS36270.
Radomes vary in shade depending on weathering, a bit like on a Typhoon. Your best bet is to check photos and then try to match them. If you're mixing then FS36270 as a basis with maybe some darker grey and a touch of brown will probably work.
Pylons and fuel tanks would be the same colour as the jet - so FS36270 - however they also would have been repainted more slowly than the jets themselves. You could, therefore, have a mix of FS36270 and FS36375.
Hope that helps.