Water-soluble copper complex formazan compounds which conform to the general formula (1) below and have useful fiber-reactive dye properties and dye carboxamido- and/or hydroxy-containing material, in particular cellulose fibers, in fast blue shades. ##STR1## in which: M is hydrogen or a salt-forming metal atom,k, m and n each denote the number zero, 1 or 2, the sum (k+m+n) being equal to 1 to 4,A is a benzene or napththalene ring which additionally can contain the fiber-reactive group --NH--Q and further substituents,B is a benzene or naphthalene ring which additionally contains the fiber-reactive group --NH--Q and further substituents,D is substituted or unsubstituted alkylene of 1 to 8 carbon atoms or is a benzene or naphthalene ring having optionally additional substituents or is a heterocyclic radical,X is a sulfo group or an oxy or carbonyloxy group,r is the number 1 or 2,Q is a radical of the formula (2) ##STR2## in which Y is halogen, Z is vinyl or a .beta.-substituted ethyl,G is the thio or an amino group --N(R)-- where R is equal to hydrogen or to low, substituted or unsubstituted alkyl or a group --K--W.sub.p defined hereinafter, K is alkylene or arylene or arylene-alkylene or alkylene-arylene whose arylene and alkylene radicals can be substituted and/or interrupted by a hetero group, W is a water-solubilizing group and p is the number 1, 2 or 3,the group --NH--Q is bonded to an aromatic carbon atom of A or B or D or to an aliphatic carbon atom of D or of a substituent on A or B, in the case of r=2, however, not simultaneously to A, B or D.