Open Instagram and swipe right to open the camera (or tap your profile photo with a plus).
Create a Story.
Tap the sticker/text tools icon (Aa) to add text.
Type your text.
Tap and hold the text area to switch to background color options.
Or tap the color picker bar (bottom) and choose a solid color.
Tap Done/Save/Share to post the Story.
To use a photo background color: add a photo, then tap the pen tool and select a color.
Cover the photo area with the pen to create a solid background.
Post the Story.