I just found an unused feature in the game - the color of the water can be different.

I think this feature was used in Worms 2 - the color was chosen randomly before each round. In Armageddon and World Party (including Remastered), the water is always blue. However, the other colors are still present in the game!

By going to the WWPR folder, then into data\Water folder, you can see six folders (Blue, Blue2, Green, Purple, Red and Yellow). Only the first one is used in the game. However, by making a backup of the Blue folder and one ot the other folders, deleting the original Blue folder and renaming other copied folder into Blue, the water color will be different!

You can see the result on these two screenshots.

In Worms Armageddon, there's a special possibility to change water colour during the game. If you type /h2so4 during the game, the water will start slowly changing its colours, cycling through the range of the rainbow. Typing /h2o again will stop at the current color.