Sea Pickle light does not work in caves

I noticed the "coloured" lighting effect Sea Pickles underwater have, and so I decided to pick some and plant them in a (dry) cave for a really cool lighting effect.

Sadly, they didn't work and so I didn't get my red lit cave. I hope this gets fixed soon so I can get mah red caves! If this is "working as intended" than it's a crying shame - the lighting effect should work on land too.