VBA if value in column A then replace in column B

Hi
Im currently using this VBA code that looks at values in column A in Sheet2 and if found it removes this value in column A in Sheet1.

Sub ifFoundReplace()
Dim i As Long, ws1 As Worksheet, ws2 As Worksheet
Set ws2 = Sheets("Sheet2")
Set ws1 = Sheets("Sheet1")
    For i = 2 To ws2.Range("A" & Rows.Count).End(3).row
        ws1.Columns(1).Replace ws2.Cells(i, "A") & " ", "", xlPart
        ws1.Columns(1).Replace " " & ws2.Cells(i, "A"), "", xlPart
    Next i
End Sub

So, on Sheet1 in column A I have:

a white

b black

d white

c orange

On Sheet2 in column A I have:

a

b

d

c

When I run the VBA, as a result I have White, Black, Orange, White, without a, b, c, d, as these values are in Sheet2.

But if I have these in Sheet1 in column A:

white a

black b

white d

orange c

the code does not work properly.

Cheers