There can be a problem with red safelights with VC papers which causes a reduction in the achievable contrast range, it's similar to using pre or post flashing to reduce contrast.
This was the reason some manufacturers like Paterson began making special VC safelights/filters.
Never heard this before. I'd like to hear the reasoning behind this.
It's clear that even red light is not entirely safe, but (provided same intensity) it cannot be more harmful than light with shorter wave length.