1: You can't change the word Forgotten in config or something. Its a Header logo wich has to be edited with Photoshop or Paint or similar program.
2: Choose? Explain better :S Do you mean that it's black and rest is grey?
Forgotten. You can change that in your server folder, config.lua chnage serverName to your serevrname.
Background color in the layout folder /your layoutname/ and open the css there u can find.