You can replace colors in bitmaps with the Eyedropper tool.
Up to four colors can be replaced at once.
You can also use the Transparency option to replace the transparent areas of an image with a color.
Similarly, you can use the Eyedropper to make a color on your image transparent.
Ensure that the image you are using is a bitmap (for example, BMP, GIF, JPG, or PNG) or a metafile (for example, WMF).
Choose Tools - Calculate
Click the Eyedropper icon and position the mouse pointer over the color you want to replace in the image. The color appears in the box next to the eyedropper icon.
Click the color in the image. The color appears in the first Source color box and the check box next to the color is selected.
In the Replace with box, select the new color.
This replaces all occurrences of the Source color in the image.
If you want to replace another color while the dialog is open, select the check box in front of Source color in the next row and repeat steps 3 to 5.
If you want to expand or contract the color selection area, increase or decrease the tolerance of the Eyedropper tool and repeat your selection.