Aircraft have radios with which to communicate their intent. Cars do not. Pilots should be utilizing these radios even at uncontrolled airfields. A good mantra to have is that there are no uncontrolled airfields. Just pilot-controlled airfields. I will communicate my intent on the Common Traffic Advisory Frequency before entering the movement area of any pilot-controlled airfield. That includes before takeoff and after landing taxiing.
Aircraft have position lights, taxi lights, landing lights, anti-collision rotating beacons, anti-collision strobe lights, ground control, ground marshals, tower, TCAS, ADS-B, sterile cockpit rules (and recommendations for Part 91), runway incursion lighting, etc. with the limited traffic at Class G airports, a couple of more lights will not help.
On the ground, any pilot, aircraft or ground crew should remain well clear of an aircraft displaying all of its lights. And, by regulation, no aircraft should be in motion without displaying at least one of its anti-collision lighting systems. Even in the daytime (unless it was certified without a system). This is unlike a car. Cars can drive around in the daytime without headlights or taillights being on (not counting brake lights and turn signals).
In the air, red, white, and green lights are very distinguishable. Especially when close together at the wattage aircraft use. You would have to have high intensity lights to be able to distinguish between other colors like between red, orange and yellow; or between blue and green. When two aircraft are approaching one another at a closing rate between 100 knots and 1000 knots, pilots do not have the luxury of time to decipher light colors. Instead, pilots rely on the items I mentioned above as well as an explicitly spelled out right-of-way directive found in Title 14 of the Code of Federal Regulations Part 91.113.
§91.113 Right-of-way rules: Except water operations.
(a) Inapplicability. This section does not apply to the operation of an aircraft on water.
(b) General. When weather conditions permit, regardless of whether an operation is conducted under instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft. When a rule of this section gives another aircraft the right-of-way, the pilot shall give way to that aircraft and may not pass over, under, or ahead of it unless well clear.
(c) In distress. An aircraft in distress has the right-of-way over all other air traffic.
(d) Converging. When aircraft of the same category are converging at approximately the same altitude (except head-on, or nearly so), the aircraft to the other’s right has the right-of-way. If the aircraft are of different categories—
(1) A balloon has the right-of-way over any other category of aircraft;
(2) A glider has the right-of-way over an airship, powered parachute, weight-shift-control aircraft, airplane, or rotorcraft.
(3) An airship has the right-of-way over a powered parachute, weight-shift-control aircraft, airplane, or rotorcraft.
However, an aircraft towing or refueling other aircraft has the right-of-way over all other engine-driven aircraft.
(e) Approaching head-on. When aircraft are approaching each other head-on, or nearly so, each pilot of each aircraft shall alter course to the right.
(f) Overtaking. Each aircraft that is being overtaken has the right-of-way and each pilot of an overtaking aircraft shall alter course to the right to pass well clear.
(g) Landing. Aircraft, while on final approach to land or while landing, have the right-of-way over other aircraft in flight or operating on the surface, except that they shall not take advantage of this rule to force an aircraft off the runway surface which has already landed and is attempting to make way for an aircraft on final approach. When two or more aircraft are approaching an airport for the purpose of landing, the aircraft at the lower altitude has the right-of-way, but it shall not take advantage of this rule to cut in front of another which is on final approach to land or to overtake that aircraft.