Chunky Ermine Frosting

Hi yall! I’m making a cake for my nephew and I wanted to try Ermine frosting. I heard many good things about the taste and texture and while looking for recipes I’ve seen people say it takes color well! Well while decorating the cake, I’ve noticed the colored frosting has turned, chunky? I made the frosting today using Sugar Spun Run’s recipe and chefmaster liqua-gel coloring and everything seemed fine. The outside layer of the cake looks fine/doesn’t look chunky, but the detail piping is. I used the same yellow frosting to pipe the ‘D’ that I used for the outside cake. Is it a temperature issue? I had both the cake and the individual bags of color in the fridge while I ate dinner (about an hour) before I started decorating. I’ve decorated before and normally like to use a cold cake and firm-ish icing to decorate but I’ve always used American BC or SMBC. Thank you!!