The version I am currently using is a single player world on 2.74, which was originally created in version 2.7. I noticed that strawberry slimes were spawning in my caves even though I had not entered the nether. I checked out incontrol spawn json and found the below. I believe it is supposed to say strawberry slime instead of blueberry slime in the bottom section.

{
"dimension": 0,
"mob": "specialmobs:strawberryslime",
"random": 0.01,
"maxlight": 15,
"minlight": 14,
"seesky": true,
"gamestage": "enteredNether",
"maxcount": {
"amount": 2,
"perplayer": true
},
"result": "allow"
},
{
"dimension": 0,
"mob": "specialmobs:blueberryslime",
"result": "deny"
},

Good catch! Thank you! Fixed in 2.75.