This'll use the activecell's format and search for cells with that format:
Option Explicit
Sub testme()
Dim myCell As Range
Dim myKeyCellFormat As String
Dim rptWks As Worksheet
Dim curWks As Worksheet
Dim oRow As Long
Set curWks = ActiveSheet
myKeyCellFormat = ActiveCell.NumberFormat
Set rptWks = Worksheets.Add
rptWks.Range("a1").Value = "'" & myKeyCellFormat
oRow = 1
For Each myCell In curWks.UsedRange
If myCell.NumberFormat = myKeyCellFormat Then
oRow = oRow + 1
rptWks.Cells(oRow, "A").Value = myCell.Address
End If
Next myCell
End Sub
This just picks up the number format. If you mean the fill color, font color,
border (and border styles), it would need to check them, too.