Probably https://en.wikipedia.org/wiki/Azorubine , https://en.wikipedia.org/wiki/Amaranth_(dye), or another cousin from the https://en.wikipedia.org/wiki/Azo_dye s.

I knew it from 'Strawberry Milk' which made me sneeze and feel strange long ago. Since then I'm avoiding E122&E123. But haven't seen it that much in the last years. Still wouldn't want to have it. It's cheap stuff to upsell cheap products. Mix/blend some real strawberries into your milk/yoghurt, or use organic syrup, marmalade.