Alright, did some tests. I see what you mean with the golden outline.
However, as you would see in the below list, the epic flawless (golden outline) armors offer better stats/armor but not necessarily more resistances per piece. There are of course a few exceptions to the rule as always.
Craftable:
Epic Flawless Lemurian - 1 cold bar
Epic Flawless Kambujan - 1 cold bar
Epic Flawless Vanir - 2 cold bars / Regular Flawless Vanir - 1 cold bar
Epic Flawless Hyrkanian - 1 cold bar
Epic Flawless Cimmerian - 1 cold bar
Epic Flawless Reptilian - 1 cold bar
Epic Flawless Hyena Fur - 1 cold bar
Epic Flawless Zamorian Thief - 1 cold bar
Epic Flawless Zingaran Freebooter - 1 cold bar
Arena Champion’s - 2 cold bars
Godbreaker - 3 cold bars
Rusted Armor - 3 cold bars / the rest of the parts 2 cold bars
Pride of Aesir - 2 cold bars
DLC:
Epic Flawless Khitan - 2 cold bars / Regular Flawless Khitan - 1 cold bar
Epic Flawless Turanian - 2 cold bars / Regular Flawless Turanian - 1 cold bar
Legendary Drop:
Commander’s Helm - 1 cold bar
Dragonscale Helm - 5 cold bars
Legacy of the Nordheimers Helmet - 4 cold bars
Scorpion Helm - 1 cold bar
War Mammoth Boots - 1 cold bar
Solspeil Shield - 5 cold bars
https://conanexiles.gamepedia.com/Armor
EDIT1:
In most cold areas Epic Flawless Lemurian keeps me “Cold” (without 2nd perk of vitality) or “Cold” / “Soothing” (with 2nd perk of vitality) and a full set gives me 4 cold bars:
What you will notice though is when I equipped Regular (not flawless) Lemurian gear, even though each part only gives 1 bar cold resistance same as the epic flawless version, you will only get 2 cold bars for the full set instead of 4 in my previous screenshots:
EDIT 2:
Another example is Epic Flawless Hyena Fur Set (1 bar per piece up to 4 bars in total) vs Flawless Hyena Fur Set (1 bar per piece up to 2 bars in total):
EDIT 3:
If you equip 1-4 regular flawless pieces, you get 1 cold bar in total. When you equip the 5th you get the 2nd bar.
If you equip 1 epic flawless piece, you get 1 cold bar, 2 epic flawless pieces - 2 cold bars, 3 or 4 epic flawless pieces - 3 cold bars, the 5th piece gives the 4th cold bar.
EDIT4:
One last edit regarding how to obtain a lot of cold protection without much effort. Vanir Sets (which you get as drops by killing Nordheimers) give up to 3 bars cold resistance with a full set equipped even with the regular non-epic non-flawless version. The crafted flawless version (epic or non-epic) provides up to 5 bars for a full set.
The system turns out to be a bit more complicated than I thought initially. Sorry for the multiple edits but I hope this gives you a better idea how it all works.