If you know a bit of HTML, you can get away with changing a patch of text colour here and there, but if you're like most people and think "HTML" is a four-letter word, then we can help you out. There is no easy way for you to change the colour of your text in the CMS.
Why is that?
The colour of your text is set by the cascading style sheet (CSS), which is what controls how HTML elements look on your website, including the colour of text and links. These things (text and link colour, main heading colours — basically the colour palette for your website, among other things) are decided upon during the design process. The CSS is created based on the designs, so making a change to the colour of your text later on is basically making a design change. We would need to make this change for you by changing the style sheet.