I could easily do that in Paint, but since they where saved as JPGs the text was blended with the yellow, so changing the background color would seriously screw up the text. What font and settings did you use for the text? Better yet, still got uncompressed origonals?
Adobe ImageReady is probably the easiest way to create the graphics. Using Layers and behaviours you can even get it to spit out the code. IR is part of Photoshop.
If you're considering doing graphics work, forget anything except Adobe. And if you can't "acquire" it, then "The GIMP" has a new version out, and does the same stuff, for free.
That's very easy to do in Photoshop. All you need to do is draw a black oval in a new layer and set the layer mode to Color Burn, and adjust the transparency of the layer accordingly.
Adobe Image Ready:
1. Take "About Us" image and copy the color of the red oval.
2. Paint over text to make a nice solid color oval.
3. Select red oval with magic wand.
4. Copy and paste to a new layer
5. Open one of the images that need fixing.
6. Text is obviously "Arial" and took me two guesses to get the right size (11px) and weight ("Bold").
7. Type text.
8. Nudge text directly over the orginal text.
9. Switch to original layer.
10. Go back to the "About Us" image and copy the layer with the red oval on it.
11. Paste it over the original layer and under the text layer.
12. Save. Upload. Enjoy.