Linear Workflow & Blue Tint

[whersmy]

What camera response do you have set? Are you working in a linear workspace?

[frankmci]

But if use any standard octane light, it gives me that blue tint, why is that? Shouldn't octane light be neutral at 6500k?

Nope, that's not how the real world works.

It's the nature of the physics of blackbody radiation, at least as I understand it, to never truly be "white." Nothing actually emits a perfect balance of wavelengths that add up to some universally perceived or measurable "white" at any temperature. White doesn't really exist, like the color purple, other than as an ideal and as a momentary subjective perception.

Welcome to unbiased rendering!

As others have said, use Light>Main> Type: Texture if you want RGB colorspace lights.