COLOURS. 



principal branch of optics, has been pro- 

 perly denominated chromatics. See 

 CHROMATICS. 



COLOUR, in heraldry, the heraldic co- 

 lours are nine, and were anciently ex- 

 pressed by the word tincture ; viz. or, ar- 

 gent, azure, gules, sable, vert,purpure, 



tenney, and sanguine; and also by pre- 

 cious stones and planets ; the armorial 

 colours are blazoned in different terms, 

 according to the rank and dignity of the 

 person whose arms are described as fol- 

 lows : 



Grand argent are metals; and it is an 

 . nvariable rule in heraldry not to put co- 

 lour upon colour, or metal on metal : that 

 is, if the field be of a colour, the charge 

 or bearing must be of a metal. 



COLOUR, in law, is a probable or plau- 

 sible plea, though in reality false at. bot- 

 tom, and only calculated to draw the trial 

 of the cause from the jury to the judge ; 

 and therefore colour ought to be matter 

 of law, or doubtful to the jury. 



In pleading, it is a rule that no man be 

 allowed to plead specially such a plea as 

 amounts only to the general issue ; but in 

 such case he shall be driven to plead the 

 general issue, in terms by which the whole 

 question is referred to a jury. But if a 

 defendant in an assize, or action of tres- 

 pass, be desirous to refer the validity of 

 his title to the court rather than to the 

 jury, he may state his title specially, and 

 at the same time give colour to the plain- 

 tiff; or suppose him to have an appear- 

 ance or colour of title, bad indeed in point 

 of law, but of which the jury are not 

 competent judges. 



COLOUR, in calico-printing. The term 

 colour in calico-printing isapplied not only 

 to those vegetable, animal, and mineral 

 solutions, which impart their own colour 

 to the cloth on which they are applied, but 

 also improperly to those earthy or metallic 

 solutions, which, possessing little or no 

 tingent properties themselves, yet retain 

 or fix the qualities (colours) of other sub- 

 stances, when afterwards applied to the 



cloth. Thus the aetite of alumina, or prin- 

 ter's red liquor, when pure, is almost co- 

 lourless,and only becomes red by the pro- 

 cess of dyeing, as will be explained here- 

 after. The acetite of iron, or iron liquor, 

 in like manner, when used of a determi- 

 nate strength, is called black colour, and 

 when weaker, purple colour, though the 

 cloth impregnated with these solutions 

 becomes black or purple, only as being 

 raised like the other in the dye-copper. 

 1. The colours produced by means of 

 these earthy or metallic solutions (which 

 in the language of science are called mor- 

 dants) form the most valuable and impor- 

 tant series, whether considered with re- 

 gard to the almost infinite variety of 

 shades, or to their solidity and durability. 

 These colours, from the mode in which 

 they are produced, (the mordant being 

 first applied to the cloth, and the colour 

 afterwards raised by dyeing,) are called 

 dyed colours. 2. Sometimes the mordant 

 is previously mixed with a solution of co- 

 louring matter, and in that state applied 

 to the cloth, so as to paint or stain it at 

 one operation and without the process of 

 dyeing. Thus another class of colours is 

 produced, many of them possessing great 

 brilliancy indeed, but much inferior to the 

 former in durability. The colours called 

 chemical by calico-printers belong chiefly 

 to this class. 3. In the third and last 

 class we may place all those, where the 

 colouring matter is simply held in solu- 

 tion by an acid or alkali, and in this state 



