https://www.bbc.com/news/science-environment-46096317
check out the photo of the Dinosaur Deinonychus
Excerpt:
Why do some birds lay colourful eggs? From pale blue to speckled red, they come in every shade and hue.
The answer, say scientists, is that coloured eggs evolved millions of years ago in birds’ ancestors, the dinosaurs.
The patterns and colours may have served to camouflage eggs from predators as white eggs stand out more against darker backgrounds.
Thus, the likes of Oviraptor may have sat on eggs of the darkest blue rather than plain white ones.
“The dinosaur nesting world was more colourful than we thought,” Dr Jasmina Wiemann of Yale University told BBC News.
“We think that camouflage is one of the main drivers.”
The researchers detected the same two pigments that are present in colourful birds eggs in a group of dinosaurs called eumaniraptorans.