Agreed.
IE can’t handle some of the new CSS3 styles being used. It always struggles with gradients, rounded borders, etc.
Unfortunately, as a web developer, if your top priority is consistency across browsers, you are going to have to lose those CSS3 styles.
Alternatively, you can always specify a default “fallback” for IE for these styles, but it won’t always look the same.
As far as your question, the red you see in Chrome is a gradient fill. The pink you are seeing is the solid background color “fallback”. So, since IE can’t display the gradient, it uses the pink “fallback”.
If you want to change this pink, for IE users, you can use firebug to find the CSS element, and change it in your stylesheets.