Just copy and paste the code in an empty project, run it, and enjoy
VB Code:
  1. Option Explicit
  2.  
  3. Private Type tRGB
  4.     R As Integer
  5.     G As Integer
  6.     B As Integer
  7. End Type
  8.  
  9. Private Sub Form_Load()
  10.     Dim K As Single, Col1 As tRGB, Col2 As tRGB
  11.    
  12.     Me.Show
  13.     Me.ScaleMode = vbTwips
  14.     Me.WindowState = 2
  15.     DoEvents
  16.    
  17.     Randomize
  18.    
  19.     Col1.R = (235 * Rnd) + 20
  20.     Col1.G = (235 * Rnd) + 20
  21.     Col1.B = (235 * Rnd) + 20
  22.    
  23.     Col2.R = (235 * Rnd) + 20
  24.     Col2.G = (235 * Rnd) + 20
  25.     Col2.B = (235 * Rnd) + 20
  26.    
  27.     Do
  28.         For K = 0 To Me.ScaleHeight Step Screen.TwipsPerPixelY
  29.             Me.Line (0, K)-(Me.ScaleWidth, K), Colr(Col1, Col2)
  30.             Pause 0.001
  31.         Next K
  32.        
  33.         For K = Me.ScaleHeight To 0 Step -Screen.TwipsPerPixelY
  34.             Me.Line (0, K)-(Me.ScaleWidth, K), Colr(Col1, Col2)
  35.             Pause 0.001
  36.         Next K
  37.     Loop
  38. End Sub
  39.  
  40. Private Sub Pause(ByVal Interval As Double)
  41.     Dim EndTime As Double
  42.     EndTime = Timer + Interval
  43.    
  44.     Do
  45.         DoEvents
  46.     Loop Until Timer >= EndTime
  47. End Sub
  48.  
  49. 'For drawing smooth colors
  50. Private Function Colr(ByRef xRGB As tRGB, ByRef ARGB As tRGB) As Long
  51.     If ARGB.R < xRGB.R Then
  52.         ARGB.R = ARGB.R + 1
  53.     ElseIf ARGB.R > xRGB.R Then
  54.         ARGB.R = ARGB.R - 1
  55.     Else
  56.         xRGB.R = (235 * Rnd) + 20
  57.     End If
  58.    
  59.     If ARGB.G < xRGB.G Then
  60.         ARGB.G = ARGB.G + 1
  61.     ElseIf ARGB.G > xRGB.G Then
  62.         ARGB.G = ARGB.G - 1
  63.     Else
  64.         xRGB.G = (235 * Rnd) + 20
  65.     End If
  66.    
  67.     If ARGB.B < xRGB.B Then
  68.         ARGB.B = ARGB.B + 1
  69.     ElseIf ARGB.B > xRGB.B Then
  70.         ARGB.B = ARGB.B - 1
  71.     Else
  72.         xRGB.B = (235 * Rnd) + 20
  73.     End If
  74.    
  75.     Colr = RGB(ARGB.R, ARGB.G, ARGB.B)
  76. End Function
  77.  
  78. Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
  79.     Unload Me
  80.     End
  81. End Sub