Red smoke. Looks similar this nitric acid explosion. Nitric acid alone probably can't exploded in a way that would create those shockwaves. But it could be a byproduct of something else:
https://www.dailymail.co.uk/news/article-2950648/Toxic-orange-cloud-created-nitric-acid-explosion-chemical-plant-spreads-FIVE-Spanish-towns-forcing-authorities-order-stay-inside.html