hello why is my light yellow colour? The battery is full.

Is this when the shuffle is connected to your computer, and is the light flashing? If so, it will flash amber ("yellow"), even when the battery becomes fully charged, IF you have the shuffle set to Manually manage music (you load the shuffle by dragging songs to it in iTunes).

The "flashing" means Do Not Disconnect? When using the Manually manage music setting, the shuffle's "disk" is mounted continuously so you need to eject it before physically disconnecting it. If you click the small Eject button next to the iPod in the iTunes sidebar, it should stop flashing. Non-flashing light means OK to Disconnect. And if the battery is fully charged, the color should be green.

NOTE: If you use automatic syncing, then iTunes unmounts the shuffle's disk whenever it is not syncing. The light should not flash (except when syncing) and it should turn green when the battery is fully charged. And you can disconnect it without ejecting it first.

Actually, I think Apple calls it "Orange." I thought they used "Amber." But maybe I read that elsewhere... I'll start calling it Orange from now on...

Bottom line... There are three colors - Red (very low charge), Green (full or nearly full charge), and whatever you want to call it in the middle. 🙂 If what you call "Yellow" is actually Green, then you are fine. That picture looks like Green to me. Actually, it looks almost white, but Orange and Red would not look like that, so I think it's Green.

This article explains the "language of the light."

http://support.apple.com/kb/HT1510

I don't think it is ever "not solid green" (if that means it is flashing green).