apex-legends
Whenever I start a match of apex, I always see three little squares in a line, with the middle one being dotted. As soon as I get into the game though, it is gone. It is only ever there when you see the little player count loading screen thing. What is it, and if its bad (because it looks like the slow connection symbol I get some times), how can I get rid of it?
Apex Coins 
can be purchased with real-world money, or earned as part of a purchased Battle Pass. They can be used to purchase cosmetics from the Featured section of the Store, purchase Apex Packs containing semi-random cosmetics and sometimes Crafting Materials, or unlock new Legends.
Legend Tokens 
can only be earned by leveling up (or refilling your XP bar at max level). They can be used to unlock new Legends, or purchase cosmetics in the Exclusive section of the the Store.
Crafting Metals 
are randomly included in some Apex Packs. 45 Apex Packs can by earned by reaching certain player levels, or they can be purchased with Apex Coins, or they can be earned as seasonal and Battle Pass rewards. Apex Coins can be used to directly purchase any generally-available (not exclusive or seasonal) cosmetic item in the game from the Armory and Legends screens.
According to this guide and ign, gold is indeed the rarest color for weapons. The ranking is as follows:
The color scheme used in Apex Legends can be a powerful tool once you get familiar with it. The colors represent item rarity with gray being the least rare, then blue, then purple, and finally gold being the rarest. Loot dropped by eliminated players will glow the color of the rarest item that it's in the stash, making it easier for you to decide which stash to loot first.
There aren’t different tiers/rarities of individual weapons i.e. there aren’t grey, blue, and purple prowlers, but there are tiers for wearables and attachments.
For attachments, the higher the tier/rarity, the better it is. Clips of higher rarity hold more ammo, stabilizers of higher rarity give more recoil control, stocks of higher rarity provide faster raise/lower times when swapping weapons, etc. The only subjectivity comes with scopes where it depends on preference as higher tier scopes have more zoom and gold scopes have the added benefit of highlighting enemies in red and showing enemies through smoke.
Gold weapons are the exact same as non-gold versions, except they come fully kitted with attachments that cannot be swapped out. There are also two gold weapons (Kraber and Mastiff) which can only be found in care packages and will always be gold.
Gold wearables are essentially equivalent to their purple counterparts, except they provide an additional passive perk.
Best Answer
Packet Loss (red squares)
Packet loss is represented by two squares with a dotted square between them, all arranged diagonally.
This means your computer is failing to send information or receive it from the Apex server. If your character is freezing for a while then suddenly teleporting, or if you’re shooting someone and they’re not receiving damage, that might mean you’re experiencing packet loss and that the server never received information from your end.
You can also interpret it as an extreme latency. If in high latency it takes longer for information to be transferred, in package loss, some information is never transferred. And just like with latency, this issue is commonly linked to your own connection.