How to Make Cobalt Blue Buttercream – Without Using Tons of Food Coloring! Want that deep, dreamy cobalt blue but your buttercream keeps turning out too bright or neon? Here’s how to level it up…without drowning it in color! Start by making Royal Blue Buttercream ( check out my reel for the step-by-step!) Once you’ve got your Royal Blue base: 💙 Add a tiny drop of black food coloring - just enough to deepen the tone without making it muddy. 💙 Microwave the buttercream in 5-second bursts, stirri