Buy yourself a packet of very expensive cake tools

Colour your fondant the deepest shade you require and roll out fairly thinly – 1/8inch or less.
Using a knife and a straight edge cut a rectangle shape with the short side being the length of your straws.

Brush the edge with a “JUST damp” paintbrush – doesn’t have to be THIS big – it is just one that I had out at the time

Place the straw on top and using your
fingers roll the fondant over the straw.

Using a sharp thin-bladed knife trim fondant using straw as a guide.

Now roll the covered straw back and forth with your fingers on the bench – I use the fondant smoother to eliminate the finger ridges forming. This step is to conceal the seam and give a smooth finish.

Repeat process to make the number of straws that you require. If you want the tones of pink etc. keep adding white fondant to your “leftover fondant”
Finished straws can be adhered to cake (I would do a fondant base coat) using royal icing