To do that you have to edit the reel template that you want to apply to gallery items. Reel template selection is only available in Site Section settings.
Please open Global Presets, then go to Templates, click to edit the template that you apply to your gallery items.
Here you can change the color or font-size, font-weight for title or prices.
After saving the changes, you need to apply this template to Site Section. Please open Customise Design, at tab Site Section go to General.
Here at Template, please click to select the changed template, then click button Save and you are done.