When a website is being designed by a Web design Dublin company like https://www.rycomarketing.ie/ecommerce-web-design-dublin/ they will go through a process of splitting up the website creation into the information and the images that need to be included on each page of the site and then the aesthetics of the site and the way that each element functions. These two distinct splits are then coded as HTML and CSS.
HTML is concerned with the information that is displayed and CSS is responsible for how it looks. As we have developed new technology to allow us to look at websites on a variety of platforms such as tablets and mobiles phones, CSS coding has had to adapt to allow websites to be successfully viewed on each of these.
In order to allow for any changes to be made easily, the CSS code is often placed in different files. One each for the relevant attributes that are needed for desktop, tablet and mobile viewing. As more people use their phones to browse the internet today, it is incredibly important that your website is mobile user friendly. Google will reward sites that have good mobile usability and it can even help to improve your search engine rankings.
When you look at the colours that you have on your website, this is being controlled by the CSS coding and if you decided to change your branding in the future, you would be able to keep the content on your site and ask for your web developer to tweak the colours only.