1. Ethanol and acid form ethyl positive ions, which react with ether to form positively charged substances, and three ethyl groups are connected to oxygen. Is it possible that this substance has color?
2. Ether contains ether peroxide, which may be the color caused by this substance.
3. Hydrochloric acid generally contains iron ions. Is it the color produced by their coordination with ether ethanol?
1, you can try replacing ethanol with ethylene. If this is still the case, this may be the reason. For 2, you can reduce the ether with reducing agent and try again. If this phenomenon is gone, this is the reason. For 3, use more pure hydrochloric acid or some complexing agent to complex iron ions, and then try again. This is the reason why there is no phenomenon.
In short, experiment, experiment is the truth.