Please read this first.
1. I'm a experienced photographer, and I will be the first to tell you it's pointless to judge brightness or color temperature of any light using a photograph.
2. Having said the above. It is possible to compare the relative brightness and color difference of multiple lights if the camera was set to use the same exposure setting and that the same white balance is applied to all the pictures.
And this is what I have done here. I took picture of the different setups with my camera on the tripod in manual setting (same setting for all) and use only the 12v battery to power these lights. I've set the white balance to 'Daylight' ~5000K, So the closest light to daylight will appear to be whiter, the rest will be more yellow/orange. It's not critical to look at the color but rather the relative color temp difference.
I don't think I need to say much here. It's pretty obvious. This is why I love hella's projector never like or feel the need to add additional auxiliary lights.
Also please don't make comments like 'My stock light looks bright than your picture' I based my exposure value (of the pictures) from the Hella Halogen. As you know you can make any given picture brighter or dakar. But just remember if I dial the exposure value of the camera up so that the stock light looks brighter in the picture, the other 3 picture will be that much brighter than they appear now.
Lightroom (photo management software) showing that the settings are the same.
You can download the individual files here