I researched in depth whether blood is allowed in roblox play, found this article on devforum Blood, Allowed when colored? - Help and Feedback / Game Design Support - DevForum | Roblox
From what I read of the comments, many said it was allowed but with a certain restriction, not being so detailed, not having torn limbs and blood gushing everywhere. But I’ve seen people saying they had their games banned for using blood. So be careful.
When in doubt, it’s better not to use a very exaggerated blood, something simpler, nothing complex.Or choose not to use blood.