The neuroscientist Anil Seth reckons that everything we perceive is a hallucination, but sometimes it conforms with something resembling reality.
https://lab.cccb.org/en/anil-seth-reality-is-a-controlled-hallucination/
To be more explicit, colours are 'qualia' which only living beings can perceive; the different electromagnetic wavelengths that cause colour-qualia are completely different to the experiences we all know and love as 'colourfulness'.
This can be easily demonstrated by looking at this image, which shows several pinkish spheres which change colour as you alter the stripes behind them, but which
do not in fact change.
My opinion is that every UAP or UFO observation (so far) has been a 'controlled hallucination', controlled by our own internal conceptions. Sometimes these hallucinations conform with reality, but sometimes they are distortions, through no fault of our own.