Okay after more digging and trial and error I actually figured this out. You can set the color for specific source feeds with this code
eventSources: [
{url: '<?php echo get_option('fc_option_feed1'); ?>', color: '#378006',},
{url: '<?php echo get_option('fc_option_feed2'); ?>', color: '#ff83ca',},
{url: '<?php echo get_option('fc_option_feed3'); ?>', color: '#378006',}
],