Here's what GA law states:

GEORGIA CODE
Copyright 2007 by The State of Georgia
All rights reserved.

*** Current through the 2007 Regular Session ***

TITLE 40. MOTOR VEHICLES AND TRAFFIC
CHAPTER 8. EQUIPMENT AND INSPECTION OF MOTOR VEHICLES
ARTICLE 1. EQUIPMENT GENERALLY
PART 5. EQUIPMENT OF LAW ENFORCEMENT AND EMERGENCY VEHICLES

O.C.G.A. § 40-8-90 (2007)

§ 40-8-90. Restrictions on use of blue lights on vehicles


(a)(1) Except as provided in this paragraph and subsection (b) of this Code section, it shall be unlawful for any person, firm, or corporation to operate any motor vehicle equipped with or containing a device capable of producing any blue lights, whether flashing, blinking, revolving, or stationary, except:

(A) Motor vehicles owned or leased by any federal, state, or local law enforcement agency;

( Motor vehicles with a permit granted by a state agency to bear such lights; or

(C) Antique, hobby, and special interest vehicles, as defined in subsection (a) of Code Section 40-2-77, which may display a blue light or lights of up to one inch in diameter as part of any such vehicle's rear stop lamps, rear turning indicator, rear hazard lamps, and rear reflectors.

(2) Any person who violates paragraph (1) of this subsection shall be guilty of a misdemeanor.

(b) The prohibition contained in subsection (a) of this Code section shall not apply to any elected sheriff who, pursuant to an agreement between the sheriff and the county governing authority, is using his or her personal motor vehicle in a law enforcement activity, provided such vehicle is marked as provided in Code Section 40-8-91.

(c) It shall be unlawful for any person to use any motor vehicle equipped with flashing, blinking, revolving, or stationary blue lights in the commission of a felony, and, upon conviction of a violation of this subsection, the punishment shall be a fine of not less than $1,000.00 or imprisonment of not less than one year, or both.

HISTORY: Ga. L. 1966, p. 208, § 1; Ga. L. 1971, p. 781, § 1; Ga. L. 1972, p. 1092, § 1; Ga. L. 1977, p. 1012, § 1; Ga. L. 1984, p. 1193, § 1; Ga. L. 1985, p. 149, § 40; Ga. L. 1992, p. 1287, § 1; Ga. L. 2005, p. 1026, § 1/SB 178.

GEORGIA CODE
Copyright 2007 by The State of Georgia
All rights reserved.

*** Current through the 2007 Regular Session ***

TITLE 40. MOTOR VEHICLES AND TRAFFIC
CHAPTER 2. REGISTRATION AND LICENSING OF MOTOR VEHICLES
ARTICLE 3. PRESTIGE LICENSE PLATES AND SPECIAL PLATES FOR CERTAIN PERSONS AND VEHICLES

O.C.G.A. § 40-2-77 (2007)

§ 40-2-77. Special license plates for antique or hobby or special interest vehicles


(a) As used in this Code section, the term "antique or hobby or special interest vehicle" means any motor vehicle which is over 25 years old or a motor vehicle which has been designed and manufactured to resemble an antique or historical vehicle and which is owned as a collector's item and for participation in club activities, exhibitions, tours, parades, and similar uses but which may be used for general transportation.

(b) Upon application, registration, and payment of an annual registration fee of $20.00, the commissioner shall issue a special license plate, as described in this Code section, for every antique or hobby or special interest vehicle within the state which is a private passenger car, truck weighing less than 14,000 pounds, or motorcycle.

(c) For antique vehicles or hobby or special interest vehicles, said license plates shall be of metal at least four inches wide and not less than seven inches in length and shall show in bold characters the words "Antique Vehicle" or "Hobby or Special Interest Vehicle," as appropriate, the full name or the abbreviation of the name of the state, distinctive numbers or letters or a combination thereof, and other distinctive markings as in the judgment of the commissioner will to the best advantage advertise, popularize, and otherwise promote the state.

(d) The commissioner shall make such rules and regulations as necessary to ascertain compliance with all state license laws relating to use and operation of a private passenger car, truck weighing less than 14,000 pounds, or motorcycle, as applicable, before issuing these plates in lieu of the regular Georgia license plate.

(e) Special plates issued under this Code section shall be transferred to another antique or hobby or special interest vehicle as provided by Code Section 40-2-80.

(f) Any vehicle for which an antique vehicle or hobby or special interest vehicle license plate has been issued pursuant to this Code section may be operated upon the roadways of this state in the same manner and under the same conditions as any vehicle bearing a regular Georgia license plate. No owner of such antique vehicle or hobby or special interest vehicle shall be required to obtain any special permits for its operation on the roads of this state.

So, I'd expect that if you can (with a straight face) tell the officer that your bike with blue lights is a representation of a historical vehicle that is used in parades, exhibitions or as part of your club activities the laws seems to indicate that you're OK.

I'll try that and see what they say.... I think I hear them laughing already.... The red dosent seem to bother anyone, but the blue tends to ruffle feathers.

ANY BLUE lights (flashing or solid) are now illegal on any regular vehicle (including motorcycles)in Georgia. This law was passed in July of 2007. I looked at an '06 law book and installed blue on my bike and was pulled over the other night and informed of this new law.

Blue and red are going to be a problem just about anywhere. Pennsylvania allows all colors. Their law just says motorcycles are allowed to have LED pods and strips. Does not mention colors. Here's a link to their short but most accommodating law:

http://www.legis.state.pa.us/CFDOCS/Legis/PN/Public/btCheck.cfm?txtType=HTM&sessYr=2005&sessInd=0&billBody=H&billTyp=B&billNbr=0901&pn=3978

Having said all that, blue still seems to be the most common color we install (www.wykedilluzionz.com). People choose to have them for show purposes, attention getters, and conversations at the local watering holes. There are also so many kinds of remote controls that make the lights do all sorts of crazy things that people are just getting them for fun. They generally leave them off (red and blue anyway) until they arrive at their destination.