Description of the U.N. flag
The blue color is taken from a UN logo at its website at www.un.org - Pantone (PMS 279).
The flag is given as 2:3 or 3:5 or the same ratio as the national flag of the country. A light blue flag with the white emblem in the middle. The emblem consists of a circular map of the earth in azimuthal equidistant projection centered at the North Pole between two olive branches.
In Webster's Concise Encyclopedia of Flags & Coats of Arms, ed. Crampton, reprint 1985:
UN: In the center of a light blue field there is the white badge of the UN - a simplified map of the world between the North Pole and 60 degrees south with all the inhabited continents shown in outline. The map is flanked by two olive branches... Blue and white are the colors of the UN, the olive branches symbolize world peace, and the map of the world shows the extent of the UN's sphere of influence.
The map projection used is Azimuthal Equidistant, centred at the North Pole. As a consequence the parallels shown (which correspond to latitudes of 60 and 30 degrees South, Equator, and 30 and 60 degrees North) are concentric circles and the ratio of their radii is simply 5:4:3:2:1. Also shown are eight meridians (corresponding to the longitudes divisible by 45 degrees); the international 0 and 180 degrees meridians are shown vertically.
I believe that this map projection was chosen because in contrast to traditional world maps, no particular nation is emphasized.
I. DIMENSIONS OF FLAG
(1) In pursuance to article 1 of the Flag Code the proportions of the United Nations Flag shall be:
(a) Hoist (width) of the United Nations Flag-2
Fly (length) of the United Nations Flag-3;
(b) Hoist (width) of the United Nations Flag-3
Fly (length) of the United Nations Flag-5;
(c) The same proportions as those of the national flag of any country in which the United Nations Flag is flown.
(2) The emblem shall in all cases be one half of the hoist of the United Nations flag and entirely centered.
Quoted from the US Navy's "Flags, Pennants, and Customs," NTP 13(B), which for some reason best known to its compilers quotes the UN Flag Code in its entirety, despite the fact that by US regulations the UN flag can be flown aboard US Navy ships and US military installations only to honor a senior UN official paying a visit (as one would fly a foreign flag for a foreign head of state).
provides more information:
A/106 (1946) is a report of the Secretary General to the General Assembly, dated 15 October 1946. It is a discussion of the need for a symbol, and says "The present symbol which now appears on the Charter of the United Nations, as well as on badges, passes, letterheads, etc., of the United Nations is a modification of the design created by members of the Presentation Branch of the United States Office of Strategic Services in April 1945, in response to a request for a button design for the San Francisco Conference. This design may be described as follows." There follows the description of the map, including the colors, "in gold on a field of smoke-blue with all water areas in white." The Secretary General goes on, however: "In connection with the adoption of an official seal and emblem for the United Nations, however, it is important to emphasize the fact that the United Nations is not committed to the use of this or any other particular design."
A/204 (1946) is the Sixth Committee's report to the General Assembly on the seal and emblem, dated 2 December 1946. It recommends that the Assembly adopt the design with the colors specified in the same terms as the device previously used. (The main difference is that the map was expanded to cover the entire world, insofar as that is possible with a polar projection.) However, the actual resolution proposed for adoption by the Assembly does not stipulate the colors, but only "the design reproduced below."
It was this resolution that was read on the floor in the General Assembly on 7 December and unanimously adopted:
"Mr. Bailey (Australia), Rapporteur: On behalf of the Sixth Committee I read the following resolution: "The General Assembly, "1. Recognizes that it is desirable to approve a distinctive emblem of the United Nations and to authorize its use for the official seal of the Organization; "Resolves therefore that the design reproduced below shall be the emblem and distinctive sign of the United Nations and shall be used for the official seal of the Organization."
The Pantone number for the official flag of the United Nations is reportedly Pantone 279C.
ovides more information:
I think we must conclude that, whatever the intention of the design committee, the General Assembly did not specify any colors for the UN emblem, and that smoke-blue is therefore of historic interest only as the color of the original, unofficial emblem provided by the OSS. The description on the emblem at http://www.un.org/depts/dhl/maplib/flag.html is therefore misleading, drawing as it does from documents that were never approved by the General Assembly. In any case, none of the documents on the UN flag refer to smoke blue, only to "light blue."
From what I remember, the light blue background was chosen as an internationally neutral color - the color of the sky as seen from every nation on Earth.
The Flag Code of the United Nations, in pdf format can be found at http://www.un.org/depts/dhl/maplib/docs/stsgb132.pdf. It provides primary source material for a number of details. Its reference is ST/SGB/132 and is dated 01 January 1967.
Dates and applicable UN Resolutions are as follows:
92(I), 07 December 1946 Adoption of UN emblem.
167(II), 20 October 1947 Adoption of UN flag, bearing the aforementioned emblem.
19 December 1947 Issue of Flag Code, by Secretary-General, under the authority of the above referenced resolution.
11 November 1952 Flag Code amended by the Secretary-General.
01 January 1967 Regulations issued by the Secretary-General, which replace those Regulations of 11 November 1952, but not the Flag Code itself, which remains as amended on that date.
The Flag Code covers such matters as Design of flag (Article 1), Dignity of flag (2), Flag protocol (3), Use of the flag by the UN and its agencies (4), Use of flag generally (Use of flag in military operations (Article 8), Manufacture and sale of flag (Article 9), Violation (Article 10), Regulations (Article 11).
The provisions of the Regulations are similar: Dimensions of flag (I), Flag protocol (II), Use of flag generally (III), Prohibitions (IV), Mourning (V), Manufacture (VI) Alphabetical order (VII), followed by a Schedule of member nations at that date, in the English alphabetical order and a note stating that the laws of a member state should prevail in respect of any conflict which might exist.
The UN's organisation chart can be found here: http://www.un.org/aboutun/chart.html. This chart also contains a link to each organisation's web site, so as to aid those who might be interested in investigating the meaning of the many acronyms used by the UN.