"Customize" button for "Color Themes" in Administration should be related to the selected theme from dropdown

Steps to follow to reproduce:

• Hover over "XWiki"
• Click "Administer Wiki"
• Click "Presentation"
• Scroll to the "Skin" section of the page
• In the "Color Theme" area select a different color theme from the default one (e.g. "Nature")
• Click "Customize"

Result: You are taken to a different page where you may edit inline the Default Color Theme

Expected behavior & Suggestion: You should have been able to edit the theme you had selected from the drop down (in this case, "Nature")