why white paint? Some kind of magical new type of RAM unlike the more common silver ones found on earlier J-20, F22, or J35?
Maybe it is not white but the same color as all the edges (light bluish cyan). They are light and can appear white when the lighting is very bright. It is also because of the increased higher contrast with the much darker painting of the body, an illusion.
A typical example of such phenomenon below. Block A and B look to be different in brightness (a) but are actually the same (b) when reference is brought in.
Another example of faulty perception of color. Color blocks on the left sides look more saturated than the right side blocks except maybe the yellow block. The yellow blocks demonstrate opposite effect because the background color of blue make yellow more outstanding while brown/orange warmer color dilute the perception of yellow. Whether one sees this yellow dilution depends on individual.
When bringing in reference. They are of the same saturation.
The lesson is never trust low quality photos, color, brightness or details. And keep some doubt even when looking at a higher quality photo because our eyes and brains are not scientific measuring devices. By extension, don't take words for granted even if they come from a known professional because context (the reference in the example above) may be missing.