Firstly, make sure your background is not black/dark, else the Red/Orange Discus will develop peppering and the Blue/Turquoise Discus will turn very dark.
Change to blue or dark blue or any light colour background.
Reduce your driftwood to a smaller size or you can even remove it completely.
Driftwood will pose a risk of injury to the Discus.
Discus are timid fish and they easily get panicked and will run into the driftwood whenever they are frightened.
Put only soft plants or soft fake plants in your tank to prevent injury to the Discus.
I agree with Colin on the fish stocking idea.
Remove the Silver Dollars and Tinfoil Barbs and add some dither fish like Cardinal Tetras as their colours are striking and a good combination with Discus.
Other Tetras are also possible.
Make sure that the Angel fish is not bigger than the Discus, else it may attack the Discus as Angel fish is more aggressive than Discus. Discus are very peaceful fish.
Lastly, add another 3-5 Discus for them to feel more secure. The bigger the group, the better they are.
Add Red Melon, Golden Yellow/Albino Yellow, Blue Diamond/Cobalt Blue, and/or Malboro Red if you want to have a colourful tank.
But if you prefer patterned Discus, look for Blue/Red Snakeskin, Turquoise Tiger, Pigeon or Red Map Discus.
But take note that if any of the Discus pair up, you will need another tank ...probably a 20-30 gallons tank for the pair.
Also, make sure that you quarantine your dithers fish before bringing them into the tank.