Dim sht1 As Worksheet, sht2 As Worksheet
Set sht1 = Worksheets('sheet1')
Set sht2 = Worksheets('sheet2')
Application.ScreenUpdating = False
For Each Cellule1 In sht1.Range('K2:K' & sht1.Range('K65536').End(xlUp).Row)
For Each Cellule2 In sht2.Range('B25:B' & sht2.Range('B65536').End(xlUp).Row)
If Cellule1.Value = Cellule2.Value Then
Cellule1.Font.Color = vbBlue ' si trouvé bleu
Cellule2.Font.Color = vbBlue
End If
Next Cellule2
Next Cellule1
Set sht1 = Nothing
Set sht2 = Nothing
Application.ScreenUpdating = True