Novel salts of stilbene-azo or stilbene-azoxy dyestuffs, in which the cations are selected from tetra-alkylammonium, tetra-alkylammonium in combination with lithium, sodium, potassium or ammonium, and ammonium in combination with lithium, sodium or potassium, have good cold water solubility relative to known salts of such dyes. The preferred dyes have the formula ##SPC1##Wherein1. each R' is independently --SO.sub.3 .sup.-M.sup.+ or --SO.sub.3 .sup.-N.sup.+(R).sub.4,wherein each R is independently alkyl of 1 to 6 carbon atoms or alkyl of 1 to 6 carbon atoms substituted by hydroxy, cyano, halo or phenyl, andEach M.sup.+ is independently hydrogen, lithium, sodium, potassium or ammonium,With the proviso that at least one R' is --SO.sub.3 .sup.-N.sup.+(R).sub.4,2. each R' is --SO.sub.3 .sup.-M.sup.+,wherein each M.sup.+ is lithium, sodium, potassium or ammonium,With the proviso that at least one M.sup.+ is ammonium, or3. each R' is independently --SO.sub.3 .sup.-M.sup.+ or --SO.sub.3 .sup.-N.sup.+(R).sub.4,wherein each R is independently alkyl of 1 to 6 carbon atoms or alkyl of 1 to 6 carbon atoms substituted by hydroxy, cyano or halo, andEach M.sup.+ is ammonium or an alkali metal,With the proviso that at least one R' is --SO.sub.3 .sup.-M.sup.+ wherein M.sup.+ is ammonium.The dyes are useful for producing colored paper by incorporation into paper stock or by application to paper sheet. The dyed paper is fast to light and wet treatments.