if you post your code and put spaces in the h t t p s then it will not render the code as html and I can correct it. You have a bunch of extra " quotes.
Case([RAG Status],"Red","<img src="h t t ps://images.quickbase.com/si/24/221-point_red.png">", "Amber","<img src="h t t ps://images.quickbase.com/si/24/223-point_yellow.png">", "Green","<img src="h t t ps://images.quickbase.com/si/24/222-point_green.png">")
"Red","<img src=h t t ps://images.quickbase.com/si/24/221-point_red.png>", "Amber","<img src=h t t ps://images.quickbase.com/si/24/223-point_yellow.png>", "Green","<img src=h t t ps://images.quickbase.com/si/24/222-point_green.png>")
This is however not the proper code for QB i'm afraid. I tried different variations but can't find the proper context yet
syntax check replies "Please check the syntax of your formula. Look for mismatched parentheses, missing quotes, or extra brackets." and points to the first '('