How can I color dots in a xy scatterplot according to column value?

Non-VBA Solution:

You need to make an additional group of data for each color group that represent the Y values for that particular group. You can use these groups to make multiple data sets within your graph.

Here is an example using your data:

     A       B        C        D                    E                        F                            G
----------------------------------------------------------------------------------------------------------------------
1| COMPANY  XVALUE   YVALUE   GROUP                 Red                     Orange                       Green
2| Apple     45       35       red         =IF($D2="red",$C2,NA()) =IF($D2="orange",$C2,NA()) =IF($D2="green",$C2,NA())
3| Xerox     45       38       red         =IF($D3="red",$C3,NA()) =IF($D3="orange",$C3,NA()) =IF($D3="green",$C3,NA())
4| KMart     63       50       orange      =IF($D4="red",$C4,NA()) =IF($D4="orange",$C4,NA()) =IF($D4="green",$C4,NA())
5| Exxon     53       59       green       =IF($D5="red",$C5,NA()) =IF($D5="orange",$C5,NA()) =IF($D5="green",$C5,NA())

It should look like this afterwards:

     A       B        C        D          E           F          G
---------------------------------------------------------------------
1| COMPANY  XVALUE   YVALUE   GROUP       Red         Orange     Green
2| Apple     45       35       red         35         #N/A       #N/A    
3| Xerox     45       38       red         38         #N/A       #N/A
4| KMart     63       50       orange     #N/A         50        #N/A
5| Exxon     53       59       green      #N/a        #N/A        59

Now you can generate your graph using different data sets. Here is a picture showing just this example data:

You can change the series (X;Y) values to B:B ; E:E, B:B ; F:F, B:B ; G:G respectively, to make it so the graph is automatically updated when you add more data.

I answered a very similar question:

https://stackoverflow.com/a/15982217/1467082

You simply need to iterate over the series' .Points collection, and then you can assign the points' .Format.Fill.ForeColor.RGB value based on whatever criteria you need.

UPDATED

The code below will color the chart per the screenshot. This only assumes three colors are used. You can add additional case statements for other color values, and update the assignment of myColor to the appropriate RGB values for each.

Option Explicit
Sub ColorScatterPoints()
    Dim cht As Chart
    Dim srs As Series
    Dim pt As Point
    Dim p As Long
    Dim Vals$, lTrim#, rTrim#
    Dim valRange As Range, cl As Range
    Dim myColor As Long

    Set cht = ActiveSheet.ChartObjects(1).Chart
    Set srs = cht.SeriesCollection(1)

   '## Get the series Y-Values range address:
    lTrim = InStrRev(srs.Formula, ",", InStrRev(srs.Formula, ",") - 1, vbBinaryCompare) + 1
    rTrim = InStrRev(srs.Formula, ",")
    Vals = Mid(srs.Formula, lTrim, rTrim - lTrim)
    Set valRange = Range(Vals)

    For p = 1 To srs.Points.Count
        Set pt = srs.Points(p)
        Set cl = valRange(p).Offset(0, 1) '## assume color is in the next column.

        With pt.Format.Fill
            .Visible = msoTrue
            '.Solid  'I commented this out, but you can un-comment and it should still work
            '## Assign Long color value based on the cell value
            '## Add additional cases as needed.
            Select Case LCase(cl)
                Case "red"
                    myColor = RGB(255, 0, 0)
                Case "orange"
                    myColor = RGB(255, 192, 0)
                Case "green"
                    myColor = RGB(0, 255, 0)
            End Select

            .ForeColor.RGB = myColor

        End With
    Next


End Sub