I seem to really like orange flowers because a disproportionate number of the things that have begun blooming recently are orange. Not that I am complaining.
California poppy (Eschscholzia californica)
Horned poppy (Glaucium flavum var. aurantiacum)
Tassel flower (Emilia javanica)
Zinnia (Zinnia elegans)
African marigold (Tagetes erecta cv.)
More orange might be forthcoming. Other colors too, though.