Gold fringe on a flag is just decoration. Nothing more. It is used on flags displayed indoors or used for ceremonial occasions. It has no significance whatsoever.
Have you ever seen the gold fringe on a flag being flown outdoors from a flagpole?
FLAG Martial Law; "Pursuant to 4 U.S.C. chapter 1, ยงยง1, 2, & 3; Executive Order 10834, August 21, 1959; 24 F.R.6865; a military flag is a flag that resembles the regular flag of the United States, except that it has a YELLOW FRINGE border on three sides. The president of the United States designates this deviation from the regular flag, by executive order, and in his capacity as Commander-in-Chief.
FLAG Martial Law;The Placing of a fringe on the national flag, the dimensions of the flag and the arrangement of the stars in the union are matters of detail not controlled by statute, but are within the discretion of the President as commander in Chief of the Army and Navy." 34 Ops. Atty. Gen. 83.
President, Dwight David Eisenhower, by Executive Order No.10834, signed on August 21, 1959 and printed in the Federal Register at 24 F.R. 6865, pursuant to law, stated that: "A military flag is a flag that resembles the regular flag of the United States, except that it has a Yellow Fringe border on three sides."
FLAG Martial law; "The use of such a fringe is prescribed in current Army Regulation no. 260-10." 34 Ops. Atty. . Gen. 483, 485.
FLAG Martial law; "Ancient custom sanctions the use of the fringe on regimental colors and standards, but there seems to be no good reason or precedent for its use on other flags." The Adjutant General of the Army, March 28, 1924, (1925); 34 Ops. Atty. Gen. 483, 485.
There is more on different uses for this flag here...