Found this picture which is listed as being the different Officer's Rank Pips. However, the ranks aren't marked, so I was wondering if anyone can tell me what pins are what ranks? Also, would love an idea of era. I am trying to learn how to tell different CG badges apart!

 

I believe one pip is 2nd Lieutenant, 2 is 1st Lieutenant, 3 is Captain. Then in combination with a crown is Major and so on. Search British rank. I think this pic is just different pips for Coldstream Guards, maybe different eras??? Seems different regiments have different pips. I've seen that Scottish pips are different than others in the British army. But I think universally the number of pips with other devices determine rank.

I believe what you said is correct relating to the number of pips. Those shown in the original post are just unique to the CG. The difference in color or finish is likely the difference between service dress or formal dress uniforms. Service dress insignia being toned down over the more formal dress uniform insignia.