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Below given are images of various fighter jet manufacturing.

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    $\begingroup$ Most likely the metal frame. Green/yellow indicates a chemical pre-paint treatment for corrosion resistance. $\endgroup$ Commented Jun 20, 2021 at 11:25
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    $\begingroup$ ALL the composites? Technically that'd be everything at all almost that's used in any part of an aircraft including most of the metals (as those tend to be alloys). $\endgroup$
    – jwenting
    Commented Jun 21, 2021 at 6:00

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Composites in aerospace are mostly Kevlar/Epoxy and Carbon/Epoxy, with some fibreglass (which has better compression stiffness than Kevlar and is sometimes combined with it). Carbon composites are severely incompatible with aluminum galvanically, so you can't have carbon and aluminum touching (the aluminum will corrode away) and have to have some kind of barrier material between them, or an alternate metal for a load bearing connection bedded in the carbon fiber, typically, titanium.

All the green/yellowish is simply zinc chromate or zinc phosphate primer paint over aluminum, either acrylic or epoxy based (mostly epoxy these days). Polyurethane finish paints need to be applied over epoxy primers to stick properly. Cessna switched to polyurethane paints for the 172 in the mid 80s and initially didn't switch primers from what was being used for acrylic paint, and there was a big filiform corrosion (corrosion that spreads unseen under the paint film) crisis with their airplanes until they switched primers.

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