They tend to look pretty ick right before they shed, very dulled in color, etc. A freshly shed snake tends to look a lot more improved. The snake also would have likely been drinking since you are providing water for it so has rehydrated itself.

You need to carefully consider the advice given to get this snake feeling secure. Secure snakes, especially little ones tend to be better hunters and you need that baby setting down a solid feeding pattern more than anything right now.