any guesses?

[smitten with ocean life]

good evening folks! i was wondering if anyone could give me a clue on what this is? its on the rock right next to the cynarina. and its 2 different colors. blue and the bubble below it is more reddish. ive been watching it for awhile now and its slowly getting bigger. (but still pretty small)

 

[rayadog]

To me, the texture appears to be sponge-like. If I’m looking at the right thing

 

[Crabs McJones]

Red bubble algae

 

[smitten with ocean life]

well ive never seen bubble algae the size of a dime but maybe ive never seen them all!
sponge crossed my mind too but i wasnt sure why it would be 2 different colors growing together