HI -- Because of the dark beam cutting across over the top , I think you should paint the whole fireplace face the dark color , the same as the beam . Add a wider mantel or just add a 8 inch board under that mantel . Then paint the right darker wall the same as the left lighter wall . Then for décor just add a colorful picture or painting that is square and hang just an inch above mantel a little left of center . It could also be a décor item ,like one of those white porcelain animal heads or one in shiny chrome or raw light wood . But just do one distinctive item for a clean modern look. Then do the family picture collection on another wall .