Android Question Button colors

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

    Private btnRed As Button
    Private btnGreen As Button
    Private btnBlue As Button
    Private btnYellow As Button
    Private btnStart As Button
    Private btns(4) As Button
End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    Activity.LoadLayout("Layout1")
    btns(0) = btnRed
    btns(1) = btnGreen
    btns(2) = btnBlue
    btns(3) = btnYellow
End Sub
Sub Activity_Resume
End Sub
Sub Activity_Pause (UserClosed As Boolean)
End Sub
Sub btnStart_Click
    Log($"btnStart_Click()"$)
    Dim r As Int = Rnd(0,4) ' Which Button to change? 0 to 3
    Log($"RandomButton # ${r}"$)
    
    Dim btn As Button = btns(r) ' Get reference to this Button
    Log($"ButtonText = ${btn.Text}"$)
    Dim color As Int = btn.TextColor ' remember textcolor
    btn.TextColor = Colors.White ' Set Textcolor to WHITE
    Sleep(250) ' Short sleep
    btn.TextColor = color ' Restore old Textcolor
    Sleep(250) ' Another short sleep
End Sub

Sub btnStart_Click
    Log($"btnStart_Click()"$)
    Dim seq() As Int = Array As Int(0,3,2,1,1,2,3) ' Sequence of Buttons to show

    Dim time As Int = 500 ' MS to show a Color

    For Each key As Int In seq
        Dim r As Int = key
        Log($"Button # ${r}"$)
        Dim btn As Button = btns(r)
        Log($"ButtonText = ${btn.Text}"$)
        Dim color As Int = btn.TextColor
        btn.TextColor = Colors.White
        Sleep(time)
        btn.TextColor = color
        Sleep(time)
          
    Next
  
End Sub

Sub btnStart_Click
    Log($"btnStart_Click()"$)
    Dim seq() As Int = Array As Int(0,3,2,1,1,2,3) ' Sequence of Buttons to show

    Dim time As Int = 500 ' MS to show a Color

    For Each key As Int In seq
        Dim r As Int = key
        Log($"Button # ${r}"$)
        Dim btn As Button = btns(r)
        Log($"ButtonText = ${btn.Text}"$)
        Dim enabled As ColorDrawable

        Select r
            Case 0
                'Log("Red")
                enabled.Initialize(Colors.Red, 10dip)
            Case 1
                'Log("Green")
                enabled.Initialize(Colors.Green, 10dip)
            Case 2
                'Log("Blue")
                enabled.Initialize(Colors.Blue, 10dip)
            Case 3
                'Log("Yellow")
                enabled.Initialize(Colors.Yellow, 10dip)
        End Select
        
        Dim unchecked As ColorDrawable
        unchecked.Initialize(Colors.White, 10dip)

        
        Dim sld As StateListDrawable
        sld.Initialize
        sld.AddState(sld.State_Enabled, enabled)
        sld.AddState(sld.State_Disabled, unchecked)
         btn.Background = sld
        
        btn.Enabled = False
        Sleep(time)
        btn.Enabled = True
        Sleep(time)
            
    Next