On online stock photo repositories like iStock, photos of rainbows and other natural phenomena are maintained royalty free for public access and general use. These images can be used in graphic design and for a host of other reasons that make them invaluable to individuals and to professionals of all kinds.
iStock maintains a large image library that contains a huge variety of images of rainbows. These rainbows are observed in various situations ranging from manifestation above waterfalls and after rainstorms to manifestations over mountain ranges on sunny days, making for great freedom of choice for anyone trying to select an appropriate rainbow image.
Those worried about paying for access to professional photography or graphic design can circumvent that step by seeking out stock images. Finding the right rainbow is not a challenge, given the huge number of stock photo sites currently maintained on the Internet, and the job can be done simply by comparing and contrasting the different options available.
Royalty-free images free up design teams to spend more time on their actual work and less on negotiating rights and making royalty payments. Stock photos cannot be customized, making them less individually flexible to the needs of a design project, but they make up for it in sheer volume.