Monika Mrowiec is an artist out of Poland, inspired by Street Art and Aztec Art. Grey background with some white and black splatters is typical for her. she does almost every composition on wallpapers similar to this, then she adds some colors that are really intensive. she also uses metallics like silver and gold and likes to use paints that are fruity.
Here you are can see some of her works and the way she paints.