Finer Points - Colour & Haze
The term "haze", refers to translucency; like stain glass, a cider
may allow light through, colouring it, without being transparent. This is caused
by particles that remain in suspension, most obviously pectin. Full appreciation
of its subtleties, requires some background, but in-short, since apples contain
pectin, some level of haze is indicative of a natural product.
When apples are first pressed, there's generally a murky liquid in-between debris that either sinks or tends to a foam at the surface. During fermentation the production of carbon dioxide tends to force the surface plug away from the liquid, whilst further deposits are made at the vessel base. Traditional practice is to rack-off the liquid periodically, discarding the debris and progressively clarifying. With each racking there is a limited amount of oxidation, tending to a darker brown colour and acetic flavour.
In my own (limited) experience, cider apples and perry pears don't clear as easily as common dessert and cooking apples. Also the length of time between milling and pressing affects pectin levels, so slower manual methods of pressing often result in more hazy ciders. Clearer ciders are very attractive, being indicative of a clean, crisp taste, but a haze can be a veil of mystery, indicative of olde world, fuller-figured flavours.
Lighter colours are likely to be more fruity, whereas darker more cutting. There are some varieties of fruit that have red flesh and give a red or orange tint to the juice (e.g. Sops in Wine). I have also achieved this by machine juicing very red skinned apples. A relatively clear foxy red-brown cider is most attractive; a murky orange one less so.