Blue to Black, partly cause I wanted my colors lightly muted cause of the c4d was.
the Black blue I think added colors that I didn't care for a on a white background.
Or you can try it yourself.
I actually like learning to work with negatives and morphing c4ds like that cause it can work really well in the creation abstract and doing backgrounds for my texture tags. Though it's been a while since I just did the gradient and left it.