N.Y. Comp. Codes R. & Regs. tit. 22, § 1000.8
(a) Cover color.
Except in those appeals in which permission to proceed as a poor person has been granted, the cover of a hard copy brief of an appellant or petitioner shall be blue; the cover of a hard copy brief of a respondent shall be red; the cover of a hard copy reply brief shall be gray; the cover of a hard copy surreply brief shall be yellow; and the cover of a hard copy brief of an intervenor or amicus curiae shall be green. The cover of a hard copy pro se supplemental brief in a criminal appeal shall be white, as shall the cover of a hard copy brief submitted by an attorney for the child. Covers of electronically-filed briefs shall likewise be colored to the extent practicable.