How to color a half of an excel cell?

Question

Background: I need to color an excele cell in red or green color. If cell is more zero that I need to color the cell in green (in right way from the middle of the cell), if the cell is less zero I need to color the cell in red (in left way from the middle of the cell).

I use "Microsoft.Office.Interop.Excel" library.

How shall I do this?

PS Cell color changing In Excel using C# is not a duplicate, because of i want to color only half of an excel cell, not full.

Answer 1

This (a) may be cheating (b) perhaps better as a Comment (but then there would be no image) and (c) possibly stretching the significance of the [excel] tag here, but may be of some interest to mention that CF can achieve something of the sort:

ColumnB (red Fill) being formatted with a formula rule of:

=$B1<0  

and ColumnC (green Fill) with a formula rule of:

=$B1>0  

The cheating part is that B:C have been reduced in width and formatted Center Across Selection.

Something very vaguely similar with Sparklines:

In a Comment (with link to an image) @BrakNicku has pointed out that Data Bars could be applied (and the image rather proves that it is possible to half fill an Excel cell with colour). A variation, also Data Bars, is to have the length proportional to the underlying value:

Answer 2

To solve this problem, I used the given scheme:

1. Create Macros in VBA (by using mouse).
2. Rewrite the macros to a general form.
3. Save the macros in C# application.
4. Save the macros in excel file(xlsm) by C#.
5. Run the macros from C#.

The given macro:

Sub CreateGistograms(r As String)
    Range(r).Select
    Selection.FormatConditions.AddDatabar
    Selection.FormatConditions(Selection.FormatConditions.Count).ShowValue = True
    Selection.FormatConditions(Selection.FormatConditions.Count).SetFirstPriority
    With Selection.FormatConditions(1)
        .MinPoint.Modify newtype:=xlConditionValueAutomaticMin
        .MaxPoint.Modify newtype:=xlConditionValueAutomaticMax
    End With
    With Selection.FormatConditions(1).BarColor
        .Color = 8700771
            .TintAndShade = 0
        End With
        Selection.FormatConditions(1).BarFillType = xlDataBarFillGradient
        Selection.FormatConditions(1).Direction = xlContext
        Selection.FormatConditions(1).NegativeBarFormat.ColorType = xlDataBarColor
        Selection.FormatConditions(1).BarBorder.Type = xlDataBarBorderSolid
        Selection.FormatConditions(1).NegativeBarFormat.BorderColorType = _
            xlDataBarColor
        With Selection.FormatConditions(1).BarBorder.Color
            .Color = 8700771
        .TintAndShade = 0
    End With
    Selection.FormatConditions(1).AxisPosition = xlDataBarAxisAutomatic
    With Selection.FormatConditions(1).AxisColor
        .Color = 0
        .TintAndShade = 0
    End With
    With Selection.FormatConditions(1).NegativeBarFormat.Color
        .Color = 255
        .TintAndShade = 0
    End With
    With Selection.FormatConditions(1).NegativeBarFormat.BorderColor
        .Color = 255
        .TintAndShade = 0
    End With
End Sub

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