VBA: faster way to change row (or cell) color based on values without referring to cell - excel

Question

Is there in VBA faster way to change row (or cell) color based on values without referring to cell
Referring to cell each time inside loop is very slow, that's why i am looking for faster method doing it in VBA.
Table:
Amount1
Amount2
100
50
20
200
...
...
If Amount1 is greater than Amount2, entire row(or cell) is red, vice versa entire row(or cell) is green.
Thank You!

Answer 1

It would have been helpful if you had clarified why you can't use CF as suggested, but if you really can't when looping it's best to refer to directly to cells as little as possible, especially changing values or formats. Try something like this:
Sub SampleValues()
Dim bGreater As Boolean
Dim rng As Range, rRow As Range
Set rng = ActiveSheet.Range("A1:B1000")
rng.Formula = "=RANDBETWEEN(1,1000)"
rng.Value = rng.Value
End Sub
Sub RedOrGreen()
Dim clr As Long, i as long
Dim rng As Range, rRow As Range
Dim arr As Variant
Const clrMore = vbGreen, clrLessEqual = vbRed
Dim t As Single
t = Timer
Set rng = Range("A1:B1000")
arr = rng.Value
For Each rRow In rng.Rows
i = i + 1
If arr(i, 2) > arr(i, 1) Then
clr = clrMore
Else
clr = clrLessEqual
End If
If rRow.Interior.Color <> clr Then
rRow.Interior.Color = clr
End If
Next
Debug.Print Timer - t
End Sub

Answer 2

Highlight Rows
Sub HighlightRows()
Dim t As Double: t = Timer
' Define constants (adjust).
Const PROC_TITLE As String = "Highlight Rows"
Const SMALL_COL As Long = 1
Const GREAT_COL As Long = 2
Dim RowColors(): RowColors = VBA.Array(vbGreen, vbRed)
' Reference the table range.
' Turn off screen updating.
Application.ScreenUpdating = False
Dim ws As Worksheet: Set ws = ActiveSheet ' improve!
If ws.AutoFilterMode Then ws.AutoFilterMode = False
Dim trg As Range: Set trg = ws.Range("A1").CurrentRegion
' Validate rows and columns.
' Validate rows.
Dim rCount As Long: rCount = trg.Rows.Count
If rCount < 2 Then
MsgBox "No data or just headers in the range '" _
& trg.Address(0, 0) & "'.", vbCritical, PROC_TITLE
Exit Sub ' screen updating will automatically get turned on
End If
' Validate columns.
Dim cCount As Long: cCount = trg.Columns.Count
Dim MaxCol As Long: MaxCol = Application.Max(SMALL_COL, GREAT_COL)
If cCount < GREAT_COL Then
MsgBox "Column " & MaxCol & " is greater than the number " _
& "of columns (" & cCount & ") in the range ('" _
& trg.Address(0, 0) & "').", vbCritical, PROC_TITLE
Exit Sub ' screen updating will automatically get turned on
End If
' Reference and populate the helper columns.
' Insert two helper columns adjacent to the right of the table range.
trg.Offset(, cCount).Resize(, 2).Insert xlShiftToRight
' Remove this line if there is no data to the right.
' Reference the expanded table range (including the helper columns)...
Dim erg As Range: Set erg = trg.Resize(, cCount + 2) ' has headers
' ... and reference its data to be used with 'SpecialCells'.
Dim edrg As Range: Set edrg = erg.Resize(rCount - 1).Offset(1) ' no headers
' Reference the helper columns.
Dim CompareCol As Long: CompareCol = cCount + 1 ' for the auto filter
Dim crg As Range: Set crg = erg.Columns(CompareCol)
Dim irg As Range: Set irg = erg.Columns(cCount + 2)
' Write an ascending integer sequence to the Integer column.
irg.Value = ws.Evaluate("ROW(1:" & rCount & ")")
' Write the values from the criteria columns to arrays.
Dim SmallData(): SmallData = erg.Columns(SMALL_COL).Value
Dim GreatData(): GreatData = erg.Columns(GREAT_COL).Value
' Define the Compare array.
Dim CompareData(): ReDim CompareData(1 To rCount, 1 To 1)
Dim SmallVal, GreatVal, r As Long
' Write the Compare results to the Compare array
' (1 for the 1st color and 2 for the 2nd), ...
For r = 2 To rCount ' skip headers
SmallVal = SmallData(r, 1)
GreatVal = GreatData(r, 1)
If IsNumeric(SmallVal) And IsNumeric(GreatVal) Then
Select Case SmallVal
Case Is < GreatVal: CompareData(r, 1) = 1
Case Is > GreatVal: CompareData(r, 1) = 2
End Select
End If
Next r
Erase SmallData
Erase GreatData
' ... write the results from the array to the Compare column...
crg.Value = CompareData
Erase CompareData
' ... and sort the range by it.
erg.Sort crg, xlAscending, , , , , , xlYes
' Highlight the rows.
edrg.Interior.Color = xlNone ' clear previous colors
Dim vedrg As Range
For r = 1 To 2
erg.AutoFilter CompareCol, CStr(r)
On Error Resume Next ' prevent error when no filtered rows
Set vedrg = edrg.SpecialCells(xlCellTypeVisible)
On Error GoTo 0
ws.AutoFilterMode = False ' turn off the auto filter!!!
If Not vedrg Is Nothing Then
Debug.Print vedrg.Address ' only two areas are being highlighted
vedrg.Interior.Color = RowColors(r - 1) ' 'RowColors' is zero-based
Set vedrg = Nothing ' reset for the next iteration
End If
Next r
' Clean up.
' Sort the range by the Integer column restoring initial order.
erg.Sort irg, xlAscending, , , , , , xlYes
' Delete the helper columns.
crg.Resize(, 2).Delete xlShiftToLeft
' If you have removed the Insert-line, replace this line with:
'crg.Resize(, 2).Clear
' Turn on screen updating to immediately see the changes
' (if the worksheet is active) before OK-ing the message box.
Application.ScreenUpdating = True
Debug.Print Format(Timer - t, "00.000000")
' Inform.
MsgBox "Rows highlighted.", vbInformation, PROC_TITLE
End Sub