Option Explicit
Sub abc()
Dim i, j, k, t
[f:f].Font.Color = vbBlack
For i = 4 To [f4].End(xlDown).Row
t = Cells(i, "f").Value
For j = 1 To Len(t)
If Mid(t, j, 1) = "[" Then
For k = j + 1 To Len(t)
If Mid(t, k, 1) = "]" Then
Cells(i, "f").Characters(j, k - j + 1).Font.Color = vbRed
j = k: Exit For
End If
Next
End If
Next
Next
End Sub
Sub abc()
Dim i, j, k, t
[f:f].Font.Color = vbBlack
For i = 4 To [f4].End(xlDown).Row
t = Cells(i, "f").Value
For j = 1 To Len(t)
If Mid(t, j, 1) = "[" Then
For k = j + 1 To Len(t)
If Mid(t, k, 1) = "]" Then
Cells(i, "f").Characters(j, k - j + 1).Font.Color = vbRed
j = k: Exit For
End If
Next
End If
Next
Next
End Sub