Make a background any size you want, I used 500x100

Fill your blackground with black using the fill tool, now take your text tool and add your text, use a white coloured font.



Now take your gradient tool, which you can find in the tool's bar if you right click on the fill tool you should see it appear.



Change you colours to yellow and blue, or any colour, make a new layer and go across your text with the gradient too. Now press 'V' (Move Tool) and drag your gradient across to the left, just so it isn't touching the text.



Now press Ctrl+G, and you gradient should now disappear.
Go to File>Jump To>Imageready

Now that you are in Image Ready go to Window>Animation, just incase your screen isn't showing.

Click on the Duplicate Current Frame button



A second window should appear, take your move tool or press 'V', and drag your gradient across, and you should be able to see the colour changind in your text.

Finally click the tween button, which is before the duplicate button and it has 4 bubbles on it.

A window should pop up, change Frames to add to 6 and click ok, move screens should appear in your animation window, now click play and you image should start to move.

If you want to save it, go to file>Save Optimized

Final Product:

Have you dragged over your gradient at the start?

Try going to save optimized as

er... what program do you use?