it's to cover up the unappetizing natural color or if it's some kind of secret alliance with the St. Patrick's Day Industrial Complex, but all commercial melon liqueurs seem to be green, even though only a few of them are made from a melon that's actually green.
Midori uses a Japanese melon from the cantaloupe family, while Bols uses honeydew. I wasn't sure which type of melon would be best in a homemade liqueur so I tried them both. I expected honeydew to win, since the fresh honeydew melon I bought seemed more ripe and flavorful than the cantaloupe. But cantaloupe made a far superior homemade liqueur. The juicy freshness of the honeydew almost completely disappeared in the infusion, leaving only a faint rind flavor. Meanwhile, good old cantaloupe gave its natural flavor like a champ and blended well with the vodka and sugar. I've provided a simple recipe here, but a hint of mint or some lemon zest could really add a new dimension to this liqueur. You could even add some food coloring if you're a green-drinks loyalist.