[vb6] How change the font color on a commandbutton ?

The easy answers are "Don't" or "Buy a 3rd party commandbutton control that will let you change the text color". Otherwise, you can use the hack below to change the color. The button is presupposed to reside on a form with scalemode=3. Commandbutton.Name = "Command1", .Caption = "", .Tag = the caption you want. In addition, place a timer on the form; call it Timer1, set its Enabled property to false and Interval to 10. Note: the text is written with the system font. If you want another font, you'll have to create the font and select it into the command1 device context.

    Option Explicit
    
    Private Type RECT
      Left As Long
      Top As Long
      Right As Long
      Bottom As Long
    End Type
    
    Private Const DT_SINGLELINE& = &H20
    Private Const DT_CENTER& = &H1
    Private Const DT_VCENTER& = &H4
    Private Const TRANSPARENT& = 1
    Private Declare Function SetBkMode& Lib "gdi32" (ByVal hdc As Long,  _
    ByVal nBkMode As Long)
    Private Declare Function SetTextColor& Lib "gdi32" (ByVal hdc As Long, _
    ByVal crColor As Long)
    Private Declare Function GetDC& Lib "user32" (ByVal hwnd As Long)
    Private Declare Function DrawText& Lib "user32" Alias "DrawTextA" _
    (ByVal hdc As Long, ByVal lpStr As String, ByVal nCount As Long, _
    lpRect As RECT, ByVal wFormat As Long)
    
    Private Sub Command1_GotFocus()
      Timer1.Enabled = True
    End Sub
    
    Private Sub Command1_LostFocus()
      Timer1.Enabled = True
    End Sub
    
    Private Sub Command1_MouseDown(Button As Integer, Shift As Integer,  _
    x As Single, y As Single)
      PaintCaption Command1, 2, 2, vbRed
    End Sub
    
    Private Sub Command1_MouseUp(Button As Integer, Shift As Integer, _
    x As Single, y As Single)
      PaintCaption Command1, 0, 0, vbRed
    End Sub
    
    Private Sub Form_Paint()
      Timer1.Enabled = True
    End Sub
    
    Private Sub Timer1_Timer()
      PaintCaption Command1, 0, 0, vbRed
      Timer1.Enabled = False
    End Sub
    
    Private Sub PaintCaption(btn As CommandButton, ByVal x As Long, _
    ByVal y As Long, clr As Long)
      Dim dc As Long, re As RECT
      dc = GetDC(btn.hwnd)
      SetTextColor dc, clr
      SetBkMode dc, TRANSPARENT
      re.Left = x
      re.Top = y
      re.Bottom = btn.Height
      re.Right = btn.Width
      DrawText dc, btn.Tag, -1, re, DT_CENTER Or DT_VCENTER Or DT_SINGLELINE
    End Sub