From graphic designers to somebody designing on Canva for the first time, the most common mistake we see with customer submitted artwork is the colour mode being set to RGB instead of CMYK. Although changing the colour mode may seem like a quick fix, you might find yourself seeing unintentional colour changes especially on the brighter tones. It's important to start designing in the CMYK colour mode to avoid any future surprises. The RGB (monitor colour) gamut contains many more colours than CMYK (print colour) gamut has to offer.
RGB (red, green & blue) is an additive colour system where light is used to mix colours; The more light you add the brighter and more vibrant the colour becomes. When working on digital designs you’ll often be working in RGB mode because that’s how your monitor works, but the problem arises when we’re creating a design for print using an RGB based tool or trying to get a logo on a business card to match the colour you have used on your website.
CMYK (cyan, magenta, yellow & black (key)) is a subtractive colour system where inks are mixed to create a range of different hues, much like mixing paint as a traditional artist. The more ink you mix the darker the colour gets. The spectrum of colours that can be produced by this 4-colour process is much more limited and can really affect bright colours. The most affected colours are purples, greens and blues.
Below is further information regarding this on the Shutterstock website. Definitely worth a read from one of the worlds largest image provider to the graphic design market.