Hello! (Chris here)
One of my favorite techniques it to color on kraft card stock with prismacolor colored pencils. I feel like the pencils almost glow on the darker card stock colors. In this case... the brown was even more appropriate because it gave the card a sandy background to go with the sentiment. I love when things come together like that! I hope you give this a technique a try.
Materials:
STAMPS: use code TJ10Chris to save 10%: