Spells: Shaman pet 34 vs 39

[JackSmith]

I am not even sure its a bug, but...

When I was level 38 and close to 39. My pets (companions spirit gained at level 34) were mostly green and lightblue.

Then I dinged and scribed my lvl 39 pet and summoned it and my first new pet was green.

I continued to resummon pets in the hope of getting a blue one, but it didn't happen. I only had green and lightblue pets.

Obviuosly this is not a proof that something is wrong, but I am wondering. What is the difference between the level 34 and 39 shaman pet spell. If indeed there is a difference?