If the sky setup is not "None" then it is either "Physical" or "HDRI".
both of these have preset values that affect the colour of the sun in the render.
You have a few different skies to choose from in the "Weather Preset" section for physical skies or you can choose a different HDRI image if you are using those.
For both of these sky types you can use the default settings or you can go into the "Detailed" settings and explore the "Environment" section.
There you can tweak the sun colour overriding the default settings.
Barry.
One of the forum moderators.
Versions 6.5 to 25
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