Declare Sub Sleep Lib "kernel32" Alias "Sleep" (ByVal dwMilliseconds As Long)
Dim x As Integer
x = 1000
Private Sub blanco()
shape1.fillcolor = vbwhite
x = x + 1000
Sleep x
Call negro
End Sub
Private Sub negro()
shape1.fillcolor = vbblack
x = x + 1000
Sleep x
Call blanco
End Sub