Choose new buttons backgrounds colours for 13 animals games

We operate 13 games mostly dedicated to animals: [login to view URL] On our games, we have a system of quests, that allows players to progress in the game and unlock new contents & new features. Quests are sorted into different themes and each quest has a different difficulty level, ranging from Beginner ("Débutant", in French") to Intergalactif master ("Maître intergalactique", in French). When viewing the quests that belong to a theme, they are ordered by difficulty. There are 7 quests in each theme, and each quest has a small 80x80 PNG image. Right now, the images of the quests have different colours (see attached screenshot: "All the quests in a theme"): blue, green, brown... This is not very clear for players. It can be confusing. We want all the pictures of quests in a game to use the same main background colour, and differentiate only through the brightness of this background colour. The brightest will be used for the easiest quest. The darkest will be used for the most difficult quest. Therefore, for each game, you have to submit 2 to 4 sets (we'll then choose the best of them) of 7 new 80x80 buttons with a gradation of background colours that is relevant with this game's look & feel. You don't have to change the overall look & feel of the buttons / their shape, nor add anything in them: simply change their background colours. This set of new buttons will be used for all the quests of this game. We don't differentiate colours between themes: the pictures all the quests/themes of a game use the same background colours. Feel free to log on to the games in order to have a better insight of the colours they use. You can use this demonstration account: Login: demo_account Password: demodemo0