What is my joy if all hands, even the unclean, can reach into it? What is my wisdom, if even the fools can dictate to me? What is my freedom, if all creatures, even the botched and impotent, are my masters? What is my life, if I am but to bow, to agree and to obey?
-- Ayn Rand, Anthem (Chapter 11)
This.
Velocity has an Ultra-Low Viz (ULV) kit that has a grey plate carrier and a white tshirt style carrier with plate pockets. It's a pain in the ass to get into but, depending on your build/body type, you can wear a polo over the top of it and no one would guess you've got rifle rated protection on.
Just remember the rule of hard armor: Thin, light and cheap. You get to pick two.
Mick-Boy
"Men who carry rifles for a living do not seek reward outside the guild. The most cherished gift...is a nod from his peers."
nsrconsulting.net
You talk about ratings, but use a designation "3+" which is not an official NIJ rating and means different things to different manufacturers. What THREATS are you hoping to defeat? For instance, M855 green tip is NOT stopped by all 3+ plates. I am not aware of any rifle plate on the market that will defeat M855 and weighs under 4 lbs. To stop M855, you have to get a "3++" or "3+ Special Threat" or some other funky name - everyone has a different designation. For that type of rating though, the lightest I've seen is around 4.6 pounds from DFNDR, or 4.8 lbs from Armour-Wear for literally 60% cheaper. Velocity has a plate (7.62x39 (API-BZ) Multi-Hit Stand-Alone Rifle Plate) that weighs the same, but is only 0.5" thick instead of 1.1" thick so they'll conceal much better.
The white carrier will likely have to be custom manufactured. I've never seen one regularly stocked by any of the common mfgrs. If you're going to get thin plates like the Velocity ones I mentioned above, TTG has a nice low-viz carrier which is perfect for concealed wear. They might make one for you in white. http://www.trentontactical.com/ttg-wag-lo-pro/
Finally, if you're standing around on guard duty all day, I suspect you will stop wearing rifle plates after very long and just stick with your soft armor.
You are right I have not specified which threats I would like the armor to stop. I will edit the original post to reflect what I am looking for.
I have found a few 3.5 - 4 lb plates under an inch thick, still reaearching and shopping around.
The weight does not bother me that much. I've put up with much worse for longer.
Velocitas, Opprimere,
Violentia Operandi
Sure thing.
8x10" 3.8 lbs
http://m.galls.com/paraclete-speed-p...OAoaAmBP8P8HAQ
10x12" ~ 4.5lbs (close enough in my book)
https://armour-wear.com/shop/all/har...3-stand-alone/
10x12" 3.3lbs - Level 3 only.
https://hardwirellc.com/collections/...i-curved-plate
10x12" 2.8 lbs - Level 3 only.
https://hardwirellc.com/collections/...htweight-plate
10x12" 3.6 lbs - 0.5" thick. Level 3+ ICW
http://www.tyrtactical.com/products/...l-3-i-c-plate/
SAPI Medium Size 4 lbs 1.1" thick Special Threat stops M855
https://www.dfndrarmor.com/product/l...te-body-armor/
Velocitas, Opprimere,
Violentia Operandi
Here is one out of Fort Collins:
http://armor.angelintelligence.com/products/truth-snap/
This plate looks interesting: VISM B4C1012 BODY ARMOR LEVEL IV CERAMIC & PE BALLISTIC PLATE SHOOTERS CUT 10X12, 5.5lbs
http://www.combatprep.com/VISM-B4C10...-p/b4c1012.htm
If those are really the specs you want, I would buy the Velocity Systems BZ Plates. I've never seen anything to compete with them.
They come in ICW:
http://store.atarmor.com/product_p/vs-pbz.htm
or stand alone:
http://store.atarmor.com/product_p/vs-pbz-sa.htm
Most plates like that seem to drop the 7.62 Nato rating to be thinner. Like the Midwest Armor FM STX:
http://www.midwestarmor.com/body-armor/venture-fm-stx
These are heavier than you specified though.