The title of this post says about 'few words', so I want to give you simple statistics without any dwelling:
What is really worth our attention, all those clothes I could define as, theoreticly, the most expensive are mostly dyed in black. Except that hue, blue and red are the next used most often.
There are similar descriptions from Cracov, relating to local townsmen and gentry. Thanks to them, we can compare popularity of used colours in both cities and find out that black was on the first place.
It is pretty easy to make a conclusion. Silesian bourgeoisie of middle and higher class prefered high quality black and red colours. The domination of blue dye is, probably, caused by its low price. Easiness of gaining a woad (Isatis tinctoria) could reduce colouring costs. To proof this claiming I need to mention about some notes telling about selling a blue and undyed cloth in the same price. What is more, Beguines from Lübeck were required to wear blue-coloured clothes.