This shows flecks of colour left behind by several projectiles as they move.
A planet with four moons revolves around a point near the centre of the picture. As they move, the planet and moons shed projectiles in the direction of their acceleration. Before vanishing, each projectile flies a short distance, leaving behind darker and darker flecks of colour as it goes.
I chose the colours to resemble Fiestaware, a brand of dinnerware popular in the era of malt shops, McCarthyism and radioactive pottery glazes. Projectiles that the planet sheds leave behind flecks of Fiesta Brilliant Red (which Fiesta discontinued in 1943 when the Manhattan Project took possession of the sources of the uranium oxide that Fiesta used to colour it). The projectiles the moons shed leave behind flecks of Fiesta Cobalt Blue, Turquoise, Turf Green or Antique Gold.