Everon does not comply with the IALA Buoyage System: Region A (introduced globally in 1980).
There are 2 global regions for the system and Everon would comply with region A due to its European heritage and location.

Basics
There are 5 types of buoy in ARMAReforger: Red, Green, Yellow, White. and Orange. Red, green, white and orange buoys have towers to raise the height of the beacon light and provide a radar cross section. Yellow buoys have a short light mast.

Function of Buoys in Reforger Everon
Red buoys indicate Port (left side when entering a channel).
Green buoys indicate Starboard (right side when entering a channel).
The function of yellow and white buoys seems to be confused. In some locations they seem to mark submerged hazards and in others they seem to be anchorage points for mooring. The models and colouring don’t really fit with the IALA scheme but I suggest the following:
Yellow buoys indicate submerged hazards/ shallow water. This doesn’t fit with IALA but Yellow=hazard is a good fit for players who don’t know maritime navigation. (Check out resources below if you want to go with real world hazard marks eg: Isolated danger marks and New danger marks).
White buoys are anchorage buoys for large vessel mooring- parked waiting for harbor access or sheltering from weather. For this purpose they need locations with 200m radius clearance and 15m draft. This can accommodate up to Handysize class bulk carriers. This is the largest class of cargo vessel that could dock at one of Everson's harbors. A Panamax or larger carrier crossing the Atlantic would bypass Everon as none of the harbors could service it.
Orange buoys- all of these are ashore. I interpret these as used to mark fishing grounds/ commercial fishery licenses and are currently ashore either due to it being off season or due to the current hostilities.

Navigation
Conventional direction of buoyage means the general direction taken by the mariner when approaching a harbor, river, estuary or other waterway from seaward. In the case of Inland Waters, the conventional direction of buoyage is going upstream. Going upstream, the left hand side is regarded as the Port Hand side and the right hand side the Starboard Hand side.
The best way of thinking about Lateral Marks- Port and Starboard buoys is that they form gates where vessels ‘drive on the right’ as they pass through them and relative to each other.

Issues
White buoys to North and South of Ile-aux-Pins GR012016
Change to yellow buoys.

Yellow buoy in Lamentin harbor GR010061
This buoy is blocking the channel in a very constrained harbor and seems to have no purpose. Delete.

Halcyon Straight- all the channel markers are green.
The best way to mark a navigation channel for the straight is to indicate it as an entrance to Southern Gulf/ Morton Bay. To do this: Change the Buoys at GR033030 and GR047032 to red buoys
Halcyon Straight Buoy locations
The buoy at GR047032 is in shallow water and should be moved southeast 50m to better mark the headland.
Also the buoys marking the western entrance to the straight are located mid-straight and would benefit from being moved further West (or add 2 additional buoys further west with the red one marking the Northern Side and the green one the Southern side)..

Goat Bay white buoys GR066038
Change both to yellow (warning) or delete one and move the other into the middle of the bay and change into a white mooring buoy.

Stubwood Point White Buoy GR062021
Change to yellow buoy if marking a hazard or delete.

Fleet Bay relocate outer channel green buoy GR106014
Move it to GR119011 so it conforms with the red buoy on the other side of the bay.

Skua Point white buoy GR103048
If this is a warning mark to indicate the shallows and exposed rocks- change it to a yellow buoy.

Perelle Bay orphan green buoy
Delete Green buoy at 087058- does not have a corresponding red buoy and is not marking a channel. Or exchange it for a yellow buoy if it is marking a hazard.

Red buoy to the North of Isle d’Argent GR 109091
Change to yellow buoy if purpose is to mark hazard

Tyrone Bay lacks an inner channel green buoy
The red buoy at GR067092 needs a companion green buoy to indicate the inner channel. A good spot for one is GR066094

Erquy Harbor has no Channel Markers GR105117
As the only permanently inhabited island local to Everon, some channel markers indicating the harbor make sense.

RESOURCES
https://maritime.college/Buoys-Beacons-and-Marks-National-Maritime-College.php
https://en.wikipedia.org/wiki/Lateral_mark
https://en.wikipedia.org/wiki/International_Association_of_Marine_Aids_to_Navigation_and_Lighthouse_Authorities
https://en.wikipedia.org/wiki/Handymax