Check out example codes for "double color background css". It will help you in understanding the concepts better.

Code Example 1

#grad {
  background-image: linear-gradient(to bottom right, rgba(255,0,0,0), rgba(255,0,0,1));
}

Code Example 2

.gradient {
	background-image: linear-gradient(angle, color1, color2) // angle: 90deg,  color1: red, color2:darkred
}

Code Example 3

background: linear-gradient(<angle>, color1 color1-stop-at, color2 color2-start-at);

Learn ReactJs, React Native from akashmittal.com