I emailed Nubar about the color differences between my 2 Nu Nails bottles Sunday and got their response today! Yay for quick customer service! Here's what the email says:
The color difference that you noticed has nothing to do with effect or performance; it is the same formula, it is just that we tried improving the product to make it more appealing to our clientele, and hence the different color.
If I can help you in any other way please let me know."
I actually like the white color more... but whatever floats their boat ;)