Grey home screen after power outage.

When I was changing my skin to a custom skin then my power went out. After the power came back on I reloaded Minecraft and it loaded normally until it loaded the home screen. Instead of showing the Minecraft logo and the play, achievements and store buttons it just showed a grey gradient were it was darker on the bottom then on the top and my user name was replaced with a black box. I've reloaded Minecraft many times but I haven't re downloaded in fear of losing my worlds and texture packs.