Blue dots in open challenges

I have a question. As you can see there are green dots - rated games and white dots - unrated games. 

From time to time a blue dot appears as well. It is pretty rare and I have seen them 2 or 3 times before. My question is : What do they represent?

Dammit no clue... maybe titled players?

I don't think that is correct. I've seen some titled players in short games. They appear in either of those 2 dots I've mentioned. You can recognize them when you hover over their dots and you will see their "badge": GM, IM, FM, etc.

Thank you for the answer though.

I've seen them too, think it means, only diamond members can accept the challenge.

Interesting if that is correct. I never thought that diamond members can narrow their search in that manner.  

I think blue dots are your friends.

Thank you. Now I have 2 different answers though.

Where is @Martin_Stahl when you need him...

Jk... he is hard working etc... but we need some mode lel

@zlatkod168 is right. The blue dots represent your friends. Everytime one of my friends is on live chess(rated or unrated) and blue dot appears. 

The reason for this is to make sure there is a difference between green, grey and red dots.

I have found red when you have a failed challenge, or when there is a title player.

Green is for rated play, and grey is for unrated play as you have said in the beginning of the post.

Blue could mean diamond member, but in my experiences it has always been friends, but it could be both. 

Hopefully you found your answer @nklristic 

@TeacherOfPain Thank you!! But your not a mod (jk)

lol @Foolsmateinfinity, what does that even supported to mean?

I am not a moderator, or a bot? Yeah well I'm not... lol 

Yea moderator... Lol just a joke & thanks

np

Thank you.  

ok but why cant I accept they're challenge then?

I believe these are challenges created by your friends.

There are also red dots that are challenges to you directly.

Yeah, I forgot about red ones, I saw that one once some time ago. Thanks.