That is the Lycopene.
To quote the Huel guys:
"Addition of Lycopene
Lycopene is a naturally occurring carotenoid phytonutrient. Lycopene is especially high in tomatoes and is partly responsible for their red colour (meaning that Huel may have some small slight red flecks). Lycopene is a potent antioxidant with a range of benefits (2). Antioxidants are required to quash free radicals, and can slow the aging process, reduce cardiovascular disease risk and reduce the risk of some cancers. There is particularly good evidenced that the long term use of lycopene reduces the risk of prostate cancer (4,5,6,7). We’ve added lycopene to Huel v2.0 as we feel its inclusion is of significant benefit to health."
Further info: Huel version 2.0 is now live!