On player join, If red hat, give hat and vest, If blue team give different hat and vest?

Make sure you have a morph of the Red Team and the Blue Team in ReplicatedFirst and rename the blue one to BlueMorph and the red to RedMorph. Then insert this code into a local script in ServerScriptService.

local redMorph = game.ReplicatedFirst.RedMorph
local blueMorph = game.ReplicatedFirst.BlueMorph

game.Players.PlayerAdded:Connect(function(plr)
       local char = plr.Parent
       local hum = char:FindFirstChildWhichIsA("Humanoid")
       local player = game.Players.LocalPlayer
       if player.TeamColor == "Really red" then
              local red = redMorph:Clone()
              red.Parent = game.StarterPlayer
              red.Name = "StarterCharacter"
              hum:LoadCharacter()
       end
       if player.TeamColor == "Really blue" then
              local blue = blueMorph:Clone()
              blue.Parent = game.StarterPlayer
              blue.Name = "StarterCharacter"
              hum:LoadCharacter()
       end
end)

Be aware this may not work as I am fairly new to scripting, but at least try it (also the indentation may not be correct so you may want to type it out yourself).

If this helped in any way please accept this answer.