1. 3-in-1 might not be the best solution since the final product looks white in colour.
2. Wrapping the IV lipid is the best solution. Try to change the container of lipid i.e. from current to plastic minibag or syringe (wrapped with the tubing).
3. If the patient is absolutely refusing lipid, then encourage enteral/oral feeding (on top of PN-free lipid) assuming the patient does not have severe mucositis. As I do remember for the old days, studies have shown that Enteral feeding in paediatric BMT patients with mild to moderate mucositis is superior and safer than PN.