A sunburst background, typically red and yellow striped, resembling the North Macedonian flag.
Used as the background of "アラジン神 絶対許早苗 (Zettai YuruSanae - inexcusable arajin god)", a Futaba Channel meme, and casually referred to as "Macedonian flag" due to the resemblance (such the case being in the YuruSanae Pixpedia article, its tag on Pixiv, and on Twitter).
This tag implicates sunburst (learn more).