Topic: Frame colour when selected

I do not see any config option for setting the thumb frame colour when selected.

Is it missing?

Re: Frame colour when selected

There is only one thumbnail frame color configuration option (thumbFrameColor) which is used for both a rolled-over thumbnail and a selected thumbnail.
You can distinguish between a selected thumbnail and a rolled-over thumbnail using frame widths:

thumbFrameWidth (for a regular thumbnail)
thumbHoverFrameWidth (for a rolled-over thumbnail)
thumbSelectedFrameWidth (for a selected  thumbnail)

All of these options can be found in JuiceboxBuilder-Pro's 'Customize -> Thumbnails' section.

If you really want to change the frame color of a selected thumbnail, then you'd need to do so using CSS.
Try adding the following CSS to the <head> section of your gallery's web page (changing the actual color value as required):

    .jb-thm-thumb-selected .jb-idx-thb-frame {
        border-color: #ff0000 !important;

Alternatively, you could add this CSS to the bottom of your gallery's 'jbcore/classic/theme.css' file (without the <style> ... </style> tags).

I hope this helps.