Having been tasked to slay 130 Blue Dragons by Sumona, I've discovered that Baby Blue Dragons count towards that total. While I can't vouch for the other colours of dragon, I assume it's logical to assume they do as well.

 

 

 

I've still got a while to go in my task, if you want screenies let me know.

This works with all tasks which have lower/higher level forms of the standard.

 

I thought there was something in the guide about this, but your right there isn't anything at all (I think its the RS Knowledge base which states it).

 

 

 

Nice find.

That's true, I just figured it was worth mention since they have different names, and while the task refers to one of them specifically, both fulfill it.

Thank you for your suggestion. :D It's a very helpful tip indeed. I've added a note about it to the Tips & tricks section of the slayer guide and you've been credited. Changes will appear in a few days max.