Yeah, and its not too hard to do. Go into the "img" folder of your game, then go to "system". You can edit the file named "Windows" to change the New Game, Continue, and Option buttons. Specifically, you'll have to edit that white box around the arrows. (and I'm pretty sure you have to edit the lines too, for the inside.) Also, make sure that your edited file is named "Windows". If you want to change the font too, that's a bit harder, and doesn't always work for every font, but I hope this helps you out a bit!
EDIT: Please note that this will change the boxes for your text, too. I don't think you can change the file mid-game, either.