Also known as 'Tutti I Colori Del Buio' and the title on the Spanish poster, this Spanish-Italian giallo doesn't stand out too terribly from the rest, but it's an experience anyway.
I find most Italian films, mainly the older ones, are far more of an experience than a cohesive and concise story. They're very much about the appearance, the mood, the feel of a movie...rather than the actual plot. I think Fulci and Fellini movies are a perfect example of this, case in point being 'House by the Cemetery', which in itself merits being featured at some point.
All the Colors of the Dark is no different. It is the experience, not the story, which stands out. The main character as I see it is the perfect example of a vulnerable female character depicted in most Giallo, manipulated by the world around her. The main thing that stands out is that she starts off a bit unhinged, and is basically put in the worst situations for any person with a severe mental illness. I imagine the director, Sergio Martino, must have been a big fan of 'Whatever Happened to Baby Jane'...and to illustrate that point, they've even got a Bette Davis lookalike in the trippy opening sequence.
I won't say this is the greatest Giallo film in history, because it really isn't. But it's certainly worth checking out. But as with most American cuts of any classic Italian horror, there are a couple of different versions. I'd advise watching the one with the opening dream sequence. And a warning before you consider watching the trailer, there is a bit of nipple at one point.