Nnnop.
There's an extension with the portable release (0.92) that does this automatically, but it adds a metric ton of javascript AND only has worked in a years old version of chrome so far, 42.0. All other browsers I've tried have varying errors.

I've been trying to do this for a few hours now. Basically, I want to, when object A has a onmouseover event, It's the atributes of object B to change. To depict it visually, if my pointer is over the gray square, I'd like the orange one to change color, or to have diferent opacity. https://files.ca...