Sub asd()
    Const dRh# = 15.75
    Dim rRow As Range, r As Range, r1 As Range
    
    With ActiveSheet.UsedRange
        .Interior.Color = xlNone
        For Each rRow In .Rows
            Select Case True
                Case rRow.RowHeight >= dRh
                    If r Is Nothing Then
                        Set r = rRow
                    Else
                        Set r = Union(r, rRow)
                    End If
                Case rRow.RowHeight < dRh
                    If r1 Is Nothing Then
                        Set r1 = rRow
                    Else
                        Set r1 = Union(r1, rRow)
                    End If
            End Select
        Next
    End With
    r.Rows.Interior.Color = vbRed
    r1.Rows.Interior.Color = vbGreen
    
End Sub

Sub asd()
    Const dRh# = 15.75
    Dim rRow As Range, r As Range, r1 As Range
    
    With ActiveSheet.UsedRange
        .Interior.Color = xlNone
        
        For Each rRow In .Rows
            Select Case rRow.RowHeight
            Case Is >= dRh: Call AddRange(r, rRow)
            Case Is < dRh:: Call AddRange(r1, rRow)
            End Select
        Next
    End With
    
    If Not r Is Nothing Then r.Rows.Interior.Color = vbRed
    If Not r1 Is Nothing Then r1.Rows.Interior.Color = vbGreen
    
    Set r = Nothing: Set r1 = Nothing
End Sub

Sub AddRange(rRng As Range, rRow As Range)
    If rRng Is Nothing Then
        Set rRng = rRow
    Else
        Set rRng = Union(rRng, rRow)
    End If
End Sub