– We recommend not to use any Plugins for Gallery. WordPress itself has nice system for Gallery and NewsPress Extend can use those features efficiently. Please read all of This Tutorial and you will be able to create Galleries.
– Avoiding installing more Plugins is good decision for site’s performance. You can change the Style of the WordPress Calendar WidGet using This Tutorial
– Those colors are controlled by specific Plugins. So there is very less opportunities to control them from Theme Environment but not impossible. You can try the Above Tutorial but may need expertise
