Example

@name VGUI_Simple_example
@persist F:dframe B:dbutton

if(first()) {
    #triggers the e2 in events like a button press or slider moved etc.
    runOnVgui(1)    
    
    #redefines the default players who will see the panel, otherwise its just the e2 owner and people added with :addPlayer(E)
    vguiDefaultPlayers(players()) 
    
    #creates the dframe
    F = dframe(1)
    F:center()
    F:makePopup()
    #tells the clients to create the panel, otherwise the panel will not get created
    F:create() 
    

    #creates the dbutton
    B = dbutton(2,F)
    B:setPos(50,50)
    B:setText("Click me!")
    B:create()

    timer("1sec",1000)
}elseif(clk("1sec")) {
    local C = hsv2rgb(vec((realtime()*10)%360,1,1))
    #sets the color
    F:setColor(C)
    #tells the clients to apply those changes
    F:modify()
    timer("1sec",1000)
}elseif(vguiClk()) {
    local Ply = vguiClkPlayer() #the player that triggered the e2
    local PanelID = vguiClkPanelID() #the id of the panel that he interacted with

    #some data that the panel returns. 
    #E.g. color of a DColorMixer, but in this case just the name of the button
    local Data = vguiClkValues() #or vguiClkValuesTable()
    
    print(format("Player: %s ID: %d Data: %s",Ply:name(),PanelID,Data:concat(",")))
    if(PanelID == B) {
        local C = hsv2rgb(vec((realtime()*10)%360,1,1))
        
        #sets the new color
        B:setColor(C)
        #applies the new color
        B:modify()
    }
}