The gemara asks whether the value of wool that is dyed is considered like it is wool with dye in it or do we say that since the dye isn’t tangible, we don’t view it as being made up of dye and wool. The gemara then proceeds to explain in what case there is relevance to the question. A number of attempts are rejected and then a number of cases are brought in which the question is relevant. They attempt to answer the question by bringing in sources relating to dyeing using shmita and orla produce, but in the end these proofs are rejected. Rava then raises a contradiction of the orla case and a tumah case and it is resolved. And in a tangent, Rava brings two contradictory sources relating to whether or not kedushat shviit (shmita) applies to tree not used to eating. That contradiction is also resolved.