Yes I could do that however the yellow is the primary color of the brand which would mean more than a simple change. I'd prefer to reduce the large expanse of yellow than change the primary brand color.
I also have a queasy feeling a/b testing aesthetics especially when its a brand attribute which over time may become a strength as opposed to a current weakness. In other words I think for certain things, a/b testing starts to create homogenised results and sites.
I think there's nothing wrong with the color as your brand logo, but perhaps think of making another color accent it nicely on your home page or making it a more subtle part of your color scheme. The way you have it set up on other pages is a nice compromise (even though I think it's still a bit too yellow):
I also have a queasy feeling a/b testing aesthetics especially when its a brand attribute which over time may become a strength as opposed to a current weakness. In other words I think for certain things, a/b testing starts to create homogenised results and sites.