Remove all your existing code, and just use this in the sheet module.

Code:
Private Sub Worksheet_Change(ByVal Target As Range)

    If Not Intersect(Target.Cells(1), Range("D1:E1,D4:E4")) Is Nothing Then
        Application.EnableEvents = False
    End If
    If Not Intersect(Target.Cells(1), Range("E1,E4")) Is Nothing Then
        Target.Cells(1, 0).Value = Range("G" & Application.Match(Target.Cells(1).Value, Range("H1:H10"), 0)).Value
        Target.Cells(1, 0).Resize(, 2).Interior.ColorIndex = Target.Cells(1).Value
    ElseIf Not Intersect(Target.Cells(1), Range("D1,D4")) Is Nothing Then
        Target.Cells(1, 2).Value = Range("H" & Application.Match(Target.Cells(1).Value, Range("G1:G10"), 0)).Value
        Target.Cells(1).Resize(, 2).Interior.ColorIndex = Target.Cells(1, 2).Value
    End If
    ColorBar_1
    ColorBar_2
    Application.EnableEvents = True
    
End Sub
Sub ColorBar_1()
    
    With ActiveSheet.ChartObjects("Chart 1026").Chart.SeriesCollection(1)
        .Shadow = False
        .InvertIfNegative = False
        With .Border
            .Weight = xlThin
            .LineStyle = xlAutomatic
        End With
        With .Interior
        .ColorIndex = Sheets("Sheet2").Range("$E$1").Value
        .Pattern = xlSolid
        End With
    End With
    
End Sub

Sub ColorBar_2()
    
    With ActiveSheet.ChartObjects("Chart 1026").Chart.SeriesCollection(2)
        .Shadow = False
        .InvertIfNegative = False
        With .Border
            .Weight = xlThin
            .LineStyle = xlAutomatic
        End With
        With .Interior
        .ColorIndex = Sheets("Sheet2").Range("$E$4").Value
        .Pattern = xlSolid
        End With
    End With
    
End Sub