Coloured evap line?

[Ckhw]

Just wondering if evap lines are always colourless or if they can be pink. Or is every pink line on frer positive no matter how incredibly faint?

I never had a coloured evaporation line with frer they were always grey. The blue dye tests I did have a coloured evaporation line but it was a very skinny line so knew it was evaporation line. If its coloured I'd say its positive do you have a picture?