=IF cell A1 is used in any formula in Sheet1!B:B THEN mark with green check, IF cell A1 is not used in any formula in Sheet1!B:B THEN mark it with a red X

Sub test()
    Dim rng1 As Range
    Dim rng2 As Range
    Set rng1 = Sheets(1).[a1:a10]
    Application.ScreenUpdating = False
    For Each rng2 In rng1.Cells
    If oneCellsDependents(rng2) Then
    rng2.Interior.Color = vbRed
    Else
    rng2.Interior.Color = xlNone
    End If
    Next
    Application.ScreenUpdating = True
    End Sub

Function oneCellsDependents(rng1 As Range) As Boolean
 ' written by Bill Manville
 ' With edits from PaulS
 ' this procedure  finds the  cells which are the direct precedents of the active cell
Dim rLast As Range, iLinkNum As Long, iArrowNum As Long
Dim bNewArrow As Boolean
Application.ScreenUpdating = False
rng1.ShowDependents
Set rLast = rng1
iArrowNum = 1
iLinkNum = 1
bNewArrow = True
Do
If oneCellsDependents Then Exit Do
    Do
        Application.Goto rLast
        On Error Resume Next
        rng1.NavigateArrow TowardPrecedent:=False, ArrowNumber:=iArrowNum, LinkNumber:=iLinkNum
        If Err.Number > 0 Then Exit Do
        On Error GoTo 0
        If rLast.Address(external:=True) = ActiveCell.Address(external:=True) Then Exit Do
        bNewArrow = False
                   If ActiveCell.Parent.Name = Sheets(2).Name Then
            oneCellsDependents = True
               Exit Do
        End If
        iLinkNum = iLinkNum + 1 ' try another  link
    Loop
    If bNewArrow Then Exit Do
    iLinkNum = 1
    bNewArrow = True
    iArrowNum = iArrowNum + 1 'try another arrow
Loop
rLast.Parent.ClearArrows
Application.Goto rLast
End Function