The gallery display should certainly be consistent across different browsers.
Ordinarily, the background color of the caption area can be set using the captionBackColor configuration option (in svBuilder-Pro's 'Customize -> Caption' section).
First of all, please make sure that you are using the most recent version of SimpleViewer-Pro (v2.3.2) to ensure that any bugs that were present in previous versions but which have since been fixed are not contributing to your problem.
If necessary, instructions for downloading the latest version and for upgrading existing galleries can be found here.
Please also ensure that you have the latest version of Adobe Flash Player installed in all your browsers.
Each browser needs its own version of Adobe Flash Player so please visit this web page in each of your browsers to ensure that Adobe Flash Player is up to date in all of them: https://helpx.adobe.com/flash-player.html
If this does not help, then please post the URL to your gallery so that I can take a look and try to see the problem for myself. It may help to see what configuration options your gallery uses.
Also, please let me know what browser and version number (and version of Adobe Flash Player) you see the problem in.
SimpleViewer Support Team