This provided two benefits, one was that the drag allowed the bomb to fall behind the bomber a safe distance before detonation, and the other was that it did not generate the complex pattern of shock waves that a classically curved nose created, which made it difficult to measure altitude barometrically.

[1] The Red Snow warhead had ballast added to maintain overall weight, ballistic and aerodynamic properties, and avoid further lengthy and expensive testing, and changes to the electrical power generating and airburst fuze.

Unlike contemporary United States bombs of similar destructive power, Yellow Sun did not deploy a parachute to retard its fall.

Instead, it had a completely flat nose which induced drag, thereby slowing the fall of the weapon sufficiently to permit the bomber to escape the danger zone.

Additionally, the blunt nose ensured that Yellow Sun did not encounter the transonic/supersonic shock waves which had caused many difficulties with barometric fuzing gates which had plagued an earlier weapon, Blue Danube.

Electrical power was supplied by duplicated ram-air turbines located behind the twin air intakes in the flat nose.

The earlier Blue Danube design had relied on lead–acid batteries which had proven to be both unreliable and to require time-consuming pre-flight warming.

Stage 1 was intended as an interim design to carry a one megaton Green Bamboo warhead of the "layer-cake" type thought similar to the Soviet Sloika and the US Alarm Clock concepts.

Twelve Green Grass warheads were fitted in the much larger, older casings derived from Blue Danube and known as "Violet Club".

It used a dangerously large quantity of fissile material – thought to be in excess of 70 kilograms (150 lb), and considerably more than an uncompressed critical mass.

To guard against the accidental crushing of the core into a critical condition, the shell was filled with 133,000 steel ball-bearings, weighing 450 kilograms (990 lb).

It was always envisaged that the Yellow Sun bomb casing would be adapted for successor warheads to minimise unessential development time and cost.