Why not use a pigmented urethane? I did an acid stained shop floor with a bow tie. I used a 4" grinder with a flat blade for the outline, and stained the inside with a darker stain. You could use an aqua color if you want to, but there is no rich blue with acid. As far as the oval goes, thats a little tougher. You could always laminate the vinyl between 2 coats of sealer. I'm not a fan of sticking vinyl directly to concrete, but it's not a problem if you sandwich it and seal with a urethane.