Lightbox navigation arrows

When editing the Lightbox navigation arrows, the Hover section works for the right arrow, but does not work for the left, I.E

Normal = Both arrows are Blue
Hover = Both arrows are Green
Active = Both arrows are Black

What actually happens is:

Normal = Right arrow is Blue. Left arrow is Green

When you hover over the Right arrow, it changes from Blue to Green, however the left arrow already presents the colour green even though it is not hovered over.