Why is my character so bright in DAZ Studio 6?
I don't know if it's something I did, but when I load the scene into 6, he looks like the image posted. In 4.22, which until now was the only version that didn't crash on my laptop, he was normal looking.

Comments
AFAIK, DS 6 adopted the latest version of OpenGL to draw the drawstyles in Viewport, so it's almost totally different from DS 4.x, especially with the texture shaded like the screenshot that you showed.
I'm afraid you have no way to change or tweak that looking ~~
You could try changing the viewport color to black. That makes it somewhat bearable to the eye or wear some sunglasses.
https://www.daz3d.com/forums/utility/thumbnail/1973921/FileUpload/7d/0f5716786dd0765c8bbb5196f77ec2.jpg
Or, Ctrl + L if Preview Lights is the cause ~~