For the first part, you could do something like this:
VB Code:
  1. Private Sub Worksheet_SelectionChange(ByVal Target As Range)
  2.  
  3.     Dim intSelSheet As Integer
  4.  
  5.     ' Check the cell to see if it's fill colour's changed to red,
  6.     ' If so, set the 1st checkbox to on.
  7.     If Range("F3").Interior.ColorIndex = 3 Then
  8.         chkCellColour1.Value = True
  9.         chkCellColour2.Value = False
  10.            
  11.     ' Otherwise, check if it's blue & set the other checkbox
  12.     ' (turning the first checkbox value to off).
  13.     ElseIf Range("F3").Interior.ColorIndex = 5 Then
  14.         chkCellColour1.Value = False
  15.         chkCellColour2.Value = True
  16.  
  17.     ' Finally, if the cell has bot been filled with blue
  18.     ' or red, turn both checkboxes to off.
  19.     Else
  20.         chkCellColour1.Value = False
  21.         chkCellColour2.Value = False
  22.     End If
  23.  
  24. End Sub

Just change the "Interior.ColorIndex" bit to read "Font.ColorIndex" depending on whether you're checking the fill or the font colour of the cell...