Just noticed that the Ridonium from the Out Of Darkness episode is also from the Clone Wars, contained in the same looking canisters, most notably being used as a way of exploding a ship in Point Of No Return from Season 5.

All TCW references are perfect, subtle and not in your face.

JEDIT: About what Erik said- https://twitter.com/RebelsReport/status/550703733806362624/photo/1

Ridonium canisters- http://screenshotcomparison.com/comparison/107503

(Cool to see how the design changes from one show to another slightly)