Gel-paste food coloring in yellow and orange, such as Wilton brand Golden Yellow and Orange
Divide marzipan into 3 pieces, keeping each piece in an airtight container when not working with it to prevent it from drying out. Dip a toothpick into gel paste and swipe across one piece of marzipan, starting with 2 swipes of yellow. (Use a fresh toothpick to add more color.)
Knead until color is even, adding more gel paste as desired. Repeat with another piece of marzipan and orange gel paste. Leave last piece untinted.
Tear off one-third each of yellow and orange marzipan; roll separately into 1/4-inch-diameter ropes, each 10 to 12 inches long. Cover both with a kitchen towel to keep from drying out. On a clean surface, roll out remaining yellow, orange, and untinted marzipan very thinly, each a scant 1/8 inch.
Cut out flowers using a 1/2-inch six-point-star aspic cutter. Make indentations in centers of each "petal" using a blade gum-paste tool (6 indentations total). Cut an 1/8-inch piece from one of the ropes and roll into a ball. Gently press ball around the tip of an arrow gum-paste tool to create a center flower "cup." Using tool, press cup into center of a flower. Repeat with remaining marzipan, creating a variety of color combinations of daffodils.
Transfer to a parchment-lined baking sheet and let stand until dry, at least 4 hours and up to overnight. Store dry flowers in an airtight container up to 5 days.