I think the blueness is because clouds at dawn and dusk reflect atmospheric colors more, whereas midday the clouds light up as more of a white from diffusing sunlight. 100% made up theory on my part, but I think it makes sense?
I asked o1 to estimate colors by hour and its reasoning and estimates seem fairly convincing[1], and also show more saturated blues dawn and dusk, though it did not model clouds.
Not sure about the accuracy of the results but the theory’s correct. The colour of sunlight changes as it passes through different thicknesses of the atmosphere and the proportion of direct light, refracted light and bounced light changes.
I asked o1 to estimate colors by hour and its reasoning and estimates seem fairly convincing[1], and also show more saturated blues dawn and dusk, though it did not model clouds.
1. https://chatgpt.com/share/67795fe3-9ac8-8009-9922-153f40c509...