I was doing a little research and couldnt find an answer about late 11th century early 12th century knights and how colourful they were.
Heraldry supposedly came in during the middle and became more common 14th century onwards.
Texts mentioning shields being of just shining metal.
Supposedly only when helmets started to cover most of the face did colours, sigils and heraldry come into play.
My question is what was the fashion for those early knights during those early days. I understand surcoates and tabards were used to protect the mail from heat and cold and potentially provide an extra layer of defence. But how colourful were they, what was the length, what materials were common (wool/linen?) and did colour signify rank or wealth during that time?.
So basically, some knights (as earlier warriors had done) used personal symbols, but there was not a formal system of heraldry. The development of heraldry coincided with a contraction and a rise in status of the knightly class, though I can't say whether that was a factor in the development of it. In any case, the knightly class of the 11th-12th century was less culturally distinct, closer to being elite soldiers than a separate institution.
The three best sources I know of for high medieval military fashion are the Bayeux Tapestry (late 11th century), the Winchester Bible (mid-to-late 12th century) and the Morgan Bible (mid-13th century).
Open-faced helmets were the norm prior to 1200, with closed-faced helmets appearing in the 13th century, as evidenced by the Morgan Bible. More helmets were probably painted than we realize, since that doesn't survive well, and Victorian collectors and antiquarians sometimes removed the remnants for that polished steel look. Maille armor became more extensive during the period, gradually moving from a short-sleeved coat and coif to a full-sleeved coat with mittens and leggings. There are a few references - from the late Middle Ages - to maille being blackened. But most of the 11th-early 12th century armor that survives is in very bad shape, and the textual and artistic evidence is weak, so it's hard to say.
Shields, by the by, were not typically made of steel. Glued-together planks or an early form of plywood were the usual materials, often covered with a layer of thick linen or leather. The Bayeux Tapestry shows both painted and unpainted shields. The Winchester Bible, which is sadly incomplete, depicts shields painted in a variety of styles, and the artwork appears more elaborate than in the Bayeux Tapestry. Likewise, the Morgan Bible shows a variety of shields, some unpainted.
Surcoats are supposed to have appeared as a direct reaction to the Crusades, but interestingly enough the Winchester Bible shows only bare maille. Surcoats are widespread in the Morgan Bible, but they are not decorated, in various primary colors (blue, green, orange). They were probably made of wool or linen, but I don't think any period examples survive.