Reference for Bava Kamma 201:9
אלא הב"ע כגון דגזל צמר וסמנין דחד וצבעיה לההוא צמר בהנך סמנין וקא מהדר ליה ניהליה לצמר יש שבח סמנין ע"ג הצמר וקא מהדר ליה סמנין וצמר או דלמא אין שבח סמנין על גבי צמר וצמר מהדר ליה סמנין לא מהדר ליה
— We must therefore be dealing here [in the query] with a case were e.g., a robber misappropriated dyes and wool of one and the same owner, and dyed that wool with those dyes and was returning to him that wool. Now, if the improvement effected by colours is a [separate] item independent of the wool, the robber would thus be returning both the dyes and the wool, but if the improvement effected by colours is not a [separate] item independent of the wool, it was only the wool which he was returning, whereas the dyes he was not returning.<span class="x" onmousemove="('comment',' And would therefore still have to pay for the dyes. ');"><sup>7</sup></span>