Mesh's vertex color won't change?

I'm making an avatar creator that has hair which you can change the color of, and I believe the best (and only) way to do this is to change the mesh's vertex color. I'm not sure if Roblox doesn't allow this, or if I'm doing something wrong in my script. Thanks for any help you can give!

game.ReplicatedStorage:WaitForChild("HairColor").OnServerEvent:Connect(function(player,r,g,b)
    local char = player.Character or player.CharacterAdded:Wait()
    for i,v in pairs(char:GetChildren()) do
        if v:IsA("Accessory") and v.Name == "Hair" and v:FindFirstChild("Handle") then
                v.Handle.Mesh.VertexColor = Vector3.new(r,g,b)
        end
    end
end)