ST. LOUIS – Another warning to parents ahead of Halloween.

Senate republicans are addressing the dangers of so-called “rainbow” fentanyl and its similarity in appearance to candy, but now some critics said the warning is more trick than treat just a month ahead of the midterm elections.

Nicknamed rainbow fentanyl, the Drug Enforcement Agency announced it had seized 15,000 of the colorful pills in a New York bust late last month, some of it hidden in a Lego box.

DEA officials told Fox News they “have not seen any connection” between the rainbow fentanyl and Halloween.

“If we see it, I promise, you have my commitment, any credible evidence, we will come out, and we will tell you,” DEA Administrator Anne Milgram said.

The DEA said it had seized rainbow fentanyl in 21 states as of late last month.