Why does the BackgroundColor3 change when I set it to a specific value?

I have a script that detects key presses within a Frame, because of the nature of the game the key input can be either right or wrong, so, therefore, I change the background color of the GUI element to let the user know if the answer he submitted (through keypresses) was correct or not. Then I set the GUI element attribute "Visible" to false and change the color back to the original [48,48,48] in readiness for the next GUI element, however, the next time that same GUI element appears, the color looks like [255,255,255] but observing the value shows me some ridiculously high numbers in the tens of thousands.

I'm not sure why it is happening, so here's my code:

local user_input = game:GetService("UserInputService")
local picked = false

user_input.InputBegan:Connect(function(key_input)
	if key_input.KeyCode == Enum.KeyCode.F and picked == false and script.Parent.Visible == true then
		picked = true
		script.Parent.BackgroundColor3 = Color3.new(0,225,0)
		wait(2)
		game.ReplicatedStorage.OptionPicked:FireServer(true)
		script.Parent.Visible = false
		script.Parent.BackgroundColor3 = Color3.new(48,48,48)
	elseif key_input.KeyCode == Enum.KeyCode.G and picked == false and script.Parent.Visible == true then
		picked = true
		script.Parent.BackgroundColor3 = Color3.new(255,0,0)
		wait(2)
		game.ReplicatedStorage.OptionPicked:FireServer(true)
		script.Parent.Visible = false
		script.Parent.BackgroundColor3 = Color3.new(48,48,48)
	end
end)

Here is the picture of the BackgroundColor3 value before and after:

Before key was pressed (Original color): https://gyazo.com/bc0902afe740f86cf562def153af12fb

During key was pressed (Appears as [0,255,0]): https://gyazo.com/aeb13a75c151faeb76798dc3aff66950

After key was pressed (Appears as [255,255,255]): https://gyazo.com/12230b9a03afa91aca9017d97b1840a9

Check this

script.Parent.BackgroundColor3 = Color3.fromRGB(255,255,255)