How do I get the tangible number values out of my function?

local textBoxA = script.Parent.RedValue
local textBoxB = script.Parent.GreenValue
local textBoxC = script.Parent.BlueValue



local function onFocusLost(enterPressed, _inputObject)
    if enterPressed then

    local textA = textBoxA.Text
    local textB = textBoxB.Text
    local textC = textBoxC.Text

        script.Parent.ImageLabel.ImageColor3 = Color3.fromRGB(textA,textB,textC)

    end
end

textBoxA.FocusLost:Connect(onFocusLost)
textBoxB.FocusLost:Connect(onFocusLost)
textBoxC.FocusLost:Connect(onFocusLost)


local RepStorageService = game:GetService("ReplicatedStorage")


local MoodLightingEvent = game.ReplicatedStorage:FindFirstChild("MoodLightEvent")

script.Parent.Execute.MouseButton1Click:Connect(function(textA,textB,textC)

    MoodLightingEvent:FireServer(textA,textB,textC)
    print("Server fired!")
end)

In this script I am attempting to pull the values out of the function called onFocusLost and parse them through the rest of script so they can be used in a remote event, problem is it returns the value in the function as nil, nil, nil whenever I do anything which I normally would assume would get the values out, such as a return.

I can not define the variables globally for the script simply because the textbox doesn't allow me too.

How can I get the values out of my function to pass them into my remote event?