Call the following code from Worksheet selection change event. This will highlight the cell for a second and then change back the color of the cell to its original.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Call CellFlash(Target, 3487637)
End Sub

Sub CellFlash(ByVal Target As Range, Optional dblFlashColor As Double = 5287936)
Dim dblColor As Double
Dim dblPattern As Double
Dim dblPatternColor As Double
Dim dblPatternColorIndex As Double
Dim dblThemeColor As Double
Dim dblTintAndShade As Double
Dim dblPatternTintAndShade As Double
Dim dblPatternThemeColor As Double
Dim dblChangeColor As Double

With Target.Interior
dblPattern = .Pattern
dblColor = .Color
dblPatternColorIndex = .PatternColorIndex
dblPatternColor = .PatternColor
dblThemeColor = .ThemeColor
dblPatternThemeColor = .PatternThemeColor
dblTintAndShade = .TintAndShade
dblPatternTintAndShade = .PatternTintAndShade
End With

With Target.Interior
If .Color = dblFlashColor Then
.Color = dblFlashColor + 1000
Else
.Color = dblFlashColor
End If
End With

Application.Wait (Now() + TimeValue("00:00:01"))

With Target.Interior
.Pattern = dblPattern
.Color = dblColor
.PatternColor = dblPatternColor
.PatternColorIndex = dblPatternColorIndex
On Error Resume Next
.PatternThemeColor = dblPatternThemeColor
.ThemeColor = dblThemeColor
Err.Clear: On Error GoTo 0: On Error GoTo -1
.TintAndShade = dblTintAndShade
.PatternTintAndShade = dblPatternTintAndShade
End With
End Sub