Transpose multiple columns to multiple rows with VBA

Here's a generic "unpivot" approach (all "fixed" columns must appear on the left of the columns to be unpivoted)

Test sub:

Sub Tester()
    
    Dim p
    
    'get the unpivoted data as a 2-D array
    p = UnPivotData(Sheets("Sheet1").Range("A1").CurrentRegion, _
                  3, False, False)
                
    With Sheets("Sheet1").Range("H1")
        .CurrentRegion.ClearContents
        .Resize(UBound(p, 1), UBound(p, 2)).Value = p 'populate array to sheet
    End With

    'EDIT: alternative (slower) method to populate the sheet
    '      from the pivoted dataset.  Might need to use this
    '      if you have a large amount of data
    'Dim r As Long, c As Long
    'For r = 1 To Ubound(p, 1)
    'For c = 1 To Ubound(p, 2)
    '    Sheets("Sheet2").Cells(r, c).Value = p(r, c)
    'Next c
    'Next r

End Sub

UnPivot function - should not need any modifications:

Function UnPivotData(rngSrc As Range, fixedCols As Long, _
                   Optional AddCategoryColumn As Boolean = True, _
                   Optional IncludeBlanks As Boolean = True)

    Dim nR As Long, nC As Long, data, dOut()
    Dim r As Long, c As Long, rOut As Long, cOut As Long, cat As Long
    Dim outRows As Long, outCols As Long
    
    data = rngSrc.Value 'get the whole table as a 2-D array
    nR = UBound(data, 1) 'how many rows
    nC = UBound(data, 2) 'how many cols

    'calculate the size of the final unpivoted table
    outRows = nR * (nC - fixedCols)
    outCols = fixedCols + IIf(AddCategoryColumn, 2, 1)
    
    'resize the output array
    ReDim dOut(1 To outRows, 1 To outCols)
               
    'populate the header row
    For c = 1 To fixedCols
        dOut(1, c) = data(1, c)
    Next c
    If AddCategoryColumn Then
        dOut(1, fixedCols + 1) = "Category"
        dOut(1, fixedCols + 2) = "Value"
    Else
        dOut(1, fixedCols + 1) = "Value"
    End If
    
    'populate the data
    rOut = 1
    For r = 2 To nR
        For cat = fixedCols + 1 To nC
            
            If IncludeBlanks Or Len(data(r, cat)) > 0 Then
                rOut = rOut + 1
                'Fixed columns...
                For c = 1 To fixedCols
                    dOut(rOut, c) = data(r, c)
                Next c
                'populate unpivoted values
                If AddCategoryColumn Then
                    dOut(rOut, fixedCols + 1) = data(1, cat)
                    dOut(rOut, fixedCols + 2) = data(r, cat)
                Else
                    dOut(rOut, fixedCols + 1) = data(r, cat)
                End If
            End If

        Next cat
    Next r
    
    UnPivotData = dOut
End Function

Here is one way (fastest?) using arrays. This approach is better that the linked question as it doesn't read and write to/from range objects in a loop. I have commented the code so you shouldn't have a problem understanding it.

Option Explicit

Sub Sample()
    Dim wsThis As Worksheet, wsThat As Worksheet
    Dim ThisAr As Variant, ThatAr As Variant
    Dim Lrow As Long, Col As Long
    Dim i As Long, k As Long

    Set wsThis = Sheet1: Set wsThat = Sheet2

    With wsThis
        '~~> Find Last Row in Col A
        Lrow = .Range("A" & .Rows.Count).End(xlUp).Row
        '~~> Find total value in D,E,F so that we can define output array
        Col = Application.WorksheetFunction.CountA(.Range("D2:F" & Lrow))

        '~~> Store the values from the range in an array
        ThisAr = .Range("A2:F" & Lrow).Value

        '~~> Define your new array
        ReDim ThatAr(1 To Col, 1 To 4)

        '~~> Loop through the array and store values in new array
        For i = LBound(ThisAr) To UBound(ThisAr)
            k = k + 1

            ThatAr(k, 1) = ThisAr(i, 1)
            ThatAr(k, 2) = ThisAr(i, 2)
            ThatAr(k, 3) = ThisAr(i, 3)

            '~~> Check for Color 1
            If ThisAr(i, 4) <> "" Then ThatAr(k, 4) = ThisAr(i, 4)

            '~~> Check for Color 2
            If ThisAr(i, 5) <> "" Then
                k = k + 1
                ThatAr(k, 1) = ThisAr(i, 1)
                ThatAr(k, 2) = ThisAr(i, 2)
                ThatAr(k, 3) = ThisAr(i, 3)
                ThatAr(k, 4) = ThisAr(i, 5)
            End If

            '~~> Check for Color 3
            If ThisAr(i, 6) <> "" Then
                k = k + 1
                ThatAr(k, 1) = ThisAr(i, 1)
                ThatAr(k, 2) = ThisAr(i, 2)
                ThatAr(k, 3) = ThisAr(i, 3)
                ThatAr(k, 4) = ThisAr(i, 6)
            End If
        Next i
    End With

    '~~> Create headers in Sheet2
    Sheet2.Range("A1:D1").Value = Sheet1.Range("A1:D1").Value

    '~~> Output the array
    wsThat.Range("A2").Resize(Col, 4).Value = ThatAr
End Sub

SHEET1

SHEET2