Tiny triangle next to altimeter

[Missedtrashday]

I am new to the game and I have been looking for information on the tiny triangle nest to the altimeter readout.  I have noticed it changing colors during my game and I can't help but think that it is trying to tell me something that would help me become a better kerbanaught, but I can't for the life of me figure out what it is!  Sometimes it appears unlit (dark gray), sometimes it is green, and sometimes it is blue.  If this has been covered in another thread I'm sorry but after numerous searches I wasn't able to find it (it could be a nomenclature problem because I don't know what the indicator is).  A link to it would be appreciated.  If it hasn't been covered but someone knows, please share your knowledge.

Thank you for your time,

Missedtrashday

[mystifeid]

I once had the same question. The other light beneath it that is sometimes orange also puzzled me. This is the answer I found.

 

[Missedtrashday]

That is totally awesome!  Thanks so much for the swift reply.  I appreciate the help.

Missedtrashday

[Gargamel]

12 hours ago, mystifeid said:

I once had the same question

I've been playing for 5 years and I still have that question.   Thanks for that link.