[belajar-excel] run time error 13 type mismatch

[KSM Absolute - Udin]

Sub sumcolor(daerah As Range)
    Dim Selrow As Range
    Dim sel As Range
    Dim SelAkhir As Range
    Dim SumKuning, SumBiru, SumHijau As Double
   
    For Each Selrow In daerah.Rows
        SumKuning = 0
        SumBiru = 0
        SumHijau = 0
        For Each sel In Selrow.Cells
            Select Case sel.Interior.Color
            Case 65535 ' Kuning
                SumKuning = SumKuning + sel.Value
            Case 12611584 ' Biru
                Nilai = sel.Value
                If Nilai > 7 Then
                    SumKuning = SumKuning + Nilai - 7
                    Nilai = 7
                End If
                SumBiru = SumBiru + Nilai
            Case 5287936  'Hijau
                Nilai = sel.Value
                If Nilai > 7 Then
                    SumKuning = SumKuning + Nilai - 7
                    Nilai = 7
                End If
                SumHijau = SumHijau + Nilai
            End Select
' untuk menyimpan posisi sel terakhir  tiap baris
            Set SelAkhir = sel
        Next
' isi julah warna
        SelAkhir.Offset(0, 1) = SumKuning
        SelAkhir.Offset(0, 2) = SumBiru
        SelAkhir.Offset(0, 3) = SumHijau
    Next
End Sub
Private Sub CommandButton1_Click()
Call sumcolor(Range("k4:As300"))
End Sub

kenapa muncul  "run time error '13' type mismatch" apa yang salah dengan kode 
ini? 
terima kasih