Me and Veronica, obviously a BOS, are dressed up in full BOS power-armour, helmets, etc. And we walk up to Helios1. The NCR guards don't bat an eye lid. Then we walk into Helios1, around, pick up solar panels. Still no-one bats an eyelid. Why?

The NCR should start shooting at us as soon as they see the armour glinting on the horizon. Is it a bug? Or an oversight?

Are you walking up in brotherhood of steel addition armor?? Or just power armor. I am pretty sure (well fairly my mind is iffy) I found BOS issue armor (doing there find the scouts quest I believe and your followers just drop it like all factional armor if ya hand it over to em. Though I am thinking you might wear it and draw some fire I just never tried it>

Nah, whilst usually companions won't touch faction gear, Veronica, being a member of the BoS, will wear their Power Armour. Same as Boone'll wear NCR gear. As to the NCR at Helios 1 not batting an eyelid, that is strange, as I thought running around with BoS armour on made the NCR hostile to you. Haven't tested this though. They never react to Veronica in BoS gear though, that much I do know.

yea go kill a BoS member wearing power amor and it should be the factions armor

Thats weird i walked up there in my PA and they started to shoot me
But it was when i clicked on the chick outside to talk to her

How is your relation with the NCR?

Yeah they never seem to care if Veronica has bos pa. They have t51b that u can buy im pretty sure. That is not brotherhood t51b.....
Even though it looks the same. Maybe you have that on.....I just get the 45d just to be sure. I ve never worn any t51b in this game.

Check the Pip-Boy. If it's called plain "T-51b Power Armor' the NCR will be fine. Is the armor green or grey?

My relation with the NCR is great. But seriously, I have a helmet on, they shouldn't know it's me until I start talking to them. And no way NCR would let a couple of BOS get that close, given the battle over Helios1. Maybe I'm over anolysing it, it just seemed really odd.

What kind of power armour?

If its just plain old T51-b then they don't care. If its Brotherhood branded they'll shoot you on sight.