Thanks for posting about this problem here. When you change your scrolling gallery color scheme in your account preferences, it is expected that your new color scheme will only be reflected in new listings to which the scrolling gallery is added to after those setting have been changed.
Since you have reported that "new" listings are still showing the old default color scheme, I suspect those "new" listings may have been posted by using the "relist" or "sell similar" option from closed listings that already contained the old scrolling gallery code within the description HTML.
If you are creating a new listing from a closed listing that already contains the HTML code for the scrolling gallery with the default color scheme, you would need to remove the scrolling gallery HTML from the description HTML during the listing process to allow the new one to be added. You can see what the scrolling gallery HTML looks like by mousing over the “Store” tab within your account and selecting the “Get HTML” option next to “Scrolling Gallery”.
If you are posting brand new listings and your new scrolling gallery colors are still not being reflected in them, I recommend contacting our customer support team for assistance by mousing over the “Help” tab and selecting the “File Support Request” option. I hope this helps.