You're a player. (Not the GM.)
You're rolling a check for something. (Whatever.)
Would you rather be rolling two green dice, or one yellow dice?
If you feel like the difficulty matters in this situation, say it is an average check with two purples.
(Please, I don't need you to quote statistics or link some statistics site. I'm not a math person; it would all just go over my head. I just want to know what you feel is the better dice pool here.)