Simply use linear-gradient as background and you can easily adjust the direction, colors, % of each color:
body {
margin: 0;
background: linear-gradient(to right, red 50%, blue 0%);
height:100vh;
text-align:center;
color:#fff;
}
some content
body {
margin: 0;
background: linear-gradient(to bottom, red 60%, blue 0%);
height:100vh;
text-align:center;
color:#fff;
}
some content
Or with pseudo-element and simple background-color then simply control the position/size of pseudo-element to control both background:
body {
margin: 0;
background: red;
height: 100vh;
position: relative;
text-align:center;
color:#fff;
}
body:before {
content: "";
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 50%;
background: blue;
z-index:-1;
}
some content
body {
margin: 0;
background: red;
height: 100vh;
position: relative;
text-align:center;
color:#fff;
}
body:before {
content: "";
position: absolute;
top: 0;
bottom: 40%;
left: 0;
right: 0;
background: blue;
z-index:-1;
}
some content
If you want more
You can combine different color inside gradient and also use multiple linear-background in order to achieve more complex color division for your background:
body {
margin: 0;
background:linear-gradient(30deg, red 50%, blue 50%, blue 70%,orange 70%) left/50% 100% no-repeat,
linear-gradient(-30deg, red 50%, blue 50%, blue 70%,orange 70%) right/50% 100% no-repeat;
height:100vh;
text-align:center;
color:#fff;
}
some content
You can also do the same with pseudo element and also use some CSS transform (rotation, skew, etc):
body {
margin: 0;
background: red;
height: 100vh;
position: relative;
text-align: center;
color: #fff;
overflow: hidden;
}
body:before {
content: "";
position: absolute;
top: 0;
bottom: 0;
left: -50%;
right: 50%;
background: blue;
transform: skew(30deg);
z-index: -1;
}
body:after {
content: "";
position: absolute;
top: 0;
bottom: 0;
left: 50%;
right: -50%;
background: orange;
transform: skew(-30deg);
z-index: -1;
}
some content
background: linear-gradient(red, yellow);
two different color – Triumph