How to change Drupal's ajax gif loader

I want to change Drupal's (6) ajax gif loader without having to change the gif itself nor tampering with core css files... but by overriding it from my theme's css.

What is the best way to ac开发者_运维知识库hieve this?

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If you mean misc/throbber.gif loader, you can simply override it in your stylesheets using html.js input.form-autocomplete and .ahah-progress .throbber css classes