I just figured this one out. Here’s what’s happening.
For example, your support site here also has a white background and color scheming similar to the Dante theme I’m using. Here is what the scroll bar color looks like here: http://glui.me/?i=sotggf9v8vxp706/2013-12-10_at_11.54_AM_2x.png/
Now here is what the scrollbar color looks like here on your Dante theme: http://glui.me/?i=ko3pdyrl15ja28v/2013-12-10_at_11.57_AM_2x.png/
The reason is that even though the Dante page appears to be white, the background color for the “body” tag was actually set to dark grey, which causes Safar to invert the scroll color for better visibility for the user. Changing this body color back to white fixes this.