Teach your baby the sign for the word rainbow in baby sign language with the following description and video.
Form the signed number 4. Touch the fingertips to the opposite shoulder. Move the hand up in an arching motion as if tracing the curve of a rainbow.
Porpora, Tracey. 2011. The complete guide to baby sign language: 101 trips and tricks every parent needs to know. Ocala, FL: Atlantic Publishing Group, Inc.