Regular detergents fading colours
I gave up on colour and liquid detergents about 3 years ago and have never looked back.
My coloured clothes have not faded anymore than they did when using even the most delicate of dedicated "colour" detergents.
Apparently oxygen bleach does not fade colours, it simply removes any loose colour, this loose colour would come out of the fabrics no matter what detergent, programme or wash temperature is used, so perhaps it is fair to say that although normal detergent will cause coloureds to fade slightly quicker, they will not fade any more than with a colour detergent. Optical brighteners do not really have all that much effect on dark colours anyway.
Colour and liquid detergents did not exist until the mid 80s-early 90s, and it wasn't really a problem before, regular detergents were marketed as being ok for woollens and the like until this time as well. I must admit I regularly wash pure wool in persil, just be mindful of the dose and it's fine! It's all down to marketing really!
Regular powder detergents do leave washing much cleaner and fresher smelling than colour care, so my coloured clothes look and feel much fresher now than they ever did before.
So I would say be brave and ditch all the specialist detergents for just one regular powder, my preference is Persil bio but Ariel bio works equally as well.
I have no rinsing problems with a full or even heavy soil dose even in soft as butter north east water.
Just make sure the machine is correctly loaded (neither over nor under) and press extra rinse if this option is available and necessary, then walk away and don't worry about it, unless your clothes feel soapy or cause rashes it's fine.
Matt