XL: RGB Function May Map to Incorrect Color

ID: Q170781

The information in this article applies to:

Microsoft Excel 97 for Windows
Microsoft Excel for Windows 95, versions 7.0, 7.0a
Microsoft Excel for Windows, versions 5.0, 5.0c

SUMMARY

When you use the RGB function in a Visual Basic for Applications macro, the color value of the RGB color of the index may be mapped to a color other than the color you expected.

For example, RGB(65,0,0) is mapped to Dark Red, but RGB(64,0,0) is mapped to Black.

The color property accepts an RGB triple and maps it to the nearest color index. When the property retrieves the color value, it returns the RGB color of the index, which may be different from the value you typed. In the example, RGB(65,0,0) is mapped to Dark Red (RGB(128,0,0)), but RGB(64,0,0) is mapped to Black (RGB(0,0,0)).

MORE INFORMATION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied, including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. This article assumes that you are familiar with the programming language being demonstrated and the tools used to create and debug procedures. Microsoft support professionals can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific needs. If you have limited programming experience, you may want to contact the Microsoft fee-based consulting line at (800) 936-5200. For more information about the support options available from Microsoft, please see the following page on the World Wide Web:

   http://www.microsoft.com/support/supportnet/refguide/

When you use an application method or property that accepts a color specification value, use a number that represents an RGB color value. An RGB color value specifies the relative intensity of the red, green, and blue colors that cause a specific color to be displayed.

The following steps assume that you created a Visual Basic module that contains the following code

   Sub ChangeRGB()

       ActiveSheet.Rectangles(1).Select
       With Selection.Interior
           .Pattern = xlSolid
           .Color = RGB([B1].Value, [B2].Value, [B3].Value)
       End With

   End Sub

and that you created a worksheet that contains the following values:

   A1: Red     B1:       C1:       D1:
   A2: Green   B2:       C2:       D2:
   A3: Blue    B3:       C3:       D3:
   A4:         B4:       C4:       D4:
   A5:         B5:       C5:       D5:

To use the sample macro, follow these steps:

 1. On the View menu, point to Toolbars, and then click Drawing.

 2. Click the Rectangle tool on the Drawing toolbar. Click cell C1 and drag
    the pointer from cell C1 to cell D5 to draw a rectangle.

 3. On the Tools menu, click Options. Then, click the Color tab.

 4. In the Standard colors group, click the first color in the second
    row (the red color).

 5. Click Modify. Then, click the Custom tab. In the Red box, change the
    value to 65. Click OK.

    Notice that the color is dark red.

 6. Click Modify. Then, click the Custom tab. Change the value of the
    Red box to 64. Click OK.

    Notice that the color is a little darker or duller than before.

 7. Click Reset. Then, click OK to close the Options dialog box.

 8. On Sheet1, enter the value 65 in cell B1.

 9. On the Tools menu, point to Macro, and then click Macros. Click
    ChangeRGB, and then click Run.

    Note that the color of the rectangle is dark red.

10. Change the value in cell B1 to 64.

11. On the Tools menu, point to Macro, and then click Macros. Click

    ChangeRGB, and then click Run.

    Note that the color of the rectangle is black.

NOTE: You can work around this problem in Microsoft Excel. The ShapeRange objects collection allows greater flexibility when you change colors in code. Instead of using Selection.Interior.Color = RGB(x,y,z), you can use Selection.ShapeRange.Fill.ForeColor.RGB = RGB(x,y,z).

REFERENCES

For more information about the ShapeRange Object collection, click the Index tab in Microsoft Visual Basic Help, type the following text

  ShapeRange

and then double-click the selected text to go to the "ShapeRange Object Collection" topic. If you are unable to find the information you need, ask the Office Assistant.

Additional query words: XL97

Keywords          : kbprg kbdta kbdtacode KbVBA 
Version           : WINDOWS:5.0,5.0c,7.0,97
Platform          : WINDOWS
Issue type        : kbprb

Last Reviewed: May 18, 1999