Here's what you can create. The original picture is first, and the effect (in one of many possible colors, i.e. infinite colors) is second. Thanks to Kristin from Howard County Library for pointing this out.
In any part of OpenOffice.org (well, except Base) you can choose insert a picture. Insert > Picture > From File or drag in a picture from the Gallery (Tools > Gallery).
Click on it, and you get the shown toolbar.
From where it says Default, select Grayscale.
Click the Color icon in the middle and you'll get the options for coloring the now-grayscale picture. If you type anything from 0 to 100 in the Red, Green, or Blue fields, you'll get dualtone color.
Combine values for two or more colors and you can get nearly any color combination. If you know or can check the RGB for the color you want, just pop it into the fields.
You can also apply effects of Brightness, Contrast, and Gamma for other effects.