tall sunflowers are dominant to short while yellow colored flowers are dominant to orange cross a plant that is heterozygous for both traits with a plant that is heterozygous for hybrid homozygous dominant for flower color

If we name the gene for sunflower height with A, then the genotypes tall sunflowers are Aa (heterozygous), AA (dominant homozygous) and for short ones aa (recessive homozygous).

If we name the gene for flower color with B, than the genotypes for yellow color are BB (dominant homozygous) and Bb (heterozygous) and for orange color bb (recessive homozygous). A cross between heterozygous for both traits and heterozygous for hybrid homozygous dominant for flower color:

P: AaBb x AaBB