With Instagram open, either swipe right or tap on the camera icon in the top-left corner to open the Stories camera. Then, take a picture or video, or select one from your library. Next, tap your finger on the screen to add text (any font) and write down whatever you want. Then, highlight the text you want to rainbow-ify.
Now, using your right thumb, press and hold on a color on the right until the gradient tool appears. Sliding your thumb up will show lighter colors while sliding down will use darker ones.
Keeping that thumb held down, take your left thumb, and hold down on the right edge of the selected text, making sure to grab that end cursor. Slowly slide both thumbs to the left at the same time and pace. You’ll see the letters change colors as you go along.
Now, of course, you can use any page of colors you want (there are three different pages of colors on Instagram). Also, you don’t have to start at the end of a gradient, you can start in the middle if you want. You could also start at the beginning so that your thumbs are moving inward toward each other instead. And you could take both thumbs left to right instead of right to left. It’s pretty versatile.
References : Gadgethacks
