I will stick to describing the meanings of the colors used. The red color used in the case of Petőfi is the color of life, motivation and passion on the one hand, and the color of anger on the other. The motif of lightning gives hints about his impulsive nature. The blue color used in the case of Kossuth stands for intellect and truth, and the shield refers to his role of president fulfilled in the National Defense Committee as well as his leading role in the war of independence.
The purple used in the case of Batthyány is the color of self-command, wisdom and intellect, and the nine circles represent the nine ministers of the first responsible government of Hungary. In the case of Széchenyi, I implied nobility, dignity and possibilities with the gold color, and the layers placed on each other represent the complex and versatile personality of Széchenyi.