Hi,
To change the colour of the letters in the accordion skin, you should change the xml file. It is in the following folder:
joomla_root/components/com_oziogallery2/skin/accordion/
and once you open it with a single text editor or any other program you may use, you will see entries for each of the items in your gallery like:
<item link="" jpg="your_picture.jpg" title="your_title" color="0x000000" alphaColor="0"><![CDATA[your_title]]></item>
The color attribute is what you should change to have the color of your choice.
Best Regards,
Yannis