You can consider the official term color trademark. Although, there isn't any guarantee that there will be any legal rights to the color or colors of a brand. One of the basic principles of color trademark laws in the US is that a functional color cannot be trademarked (e.g. the green color in John Deere).
A colour trade mark (UK spelling) or color trademark (US spelling) is a non-conventional trade mark where at least one colour is used to perform the trade mark function of uniquely identifying the commercial origin of products or services. wikipedia
Here is some relevant information about color branding and trademark rights from colormatters.com:
Even though a TM or ® symbol may appear on a brand's image, it does not mean there are any legal rights to the color or colors.
The TM and ® marks on the Mc Donald's and Starbucks images below means that the company has claimed rights to the image (the symbol or word or combination of both).
A color trademark is different. In this case, the color is the brand. The use of the color in a market sector is protected by trademark. For example, when you see chocolate candy in a purple wrapper, you know it's Cadbury: when you see a turquoise box for jewelry, you know it's from Tiffany & Co.
However, Cadbury's purple is protected by trademark only for chocolate products. Anyone else can use the color purple. For example, Royal Motor Oil and Nexium (pills) use purple in their brand.