HTML Guide - issues tagged as background

CSS: “background”: “from” is not a valid color 3 or 6 hexadecimals numbers.

background CSS property has an invalid value; "from" is not recognized as a valid color or background value.

The background property in CSS can accept color names, hex codes, rgb/rgba values, or CSS keywords, but "from" is not valid. Sometimes this error can appear if using incorrect CSS gradient syntax, where "from" is not a recognized value.

Detailed Explanation

In standard HTML and CSS, a background can be set using:

Hex color codes, such as #fff or #ffffff
Named colors, such as red or blue
Functions, such as rgb(255,0,0) or linear-gradient(...)

If you wrote something like:

background: from #fff to #000;

or

background: "from";

neither is valid CSS.

To use gradients, use correct linear-gradient() or radial-gradient() syntax:

background: linear-gradient(to right, #fff, #000);

For a solid color:

background: #fff;

HTML Examples

Incorrect CSS:

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Incorrect CSS</title>
  <style>
    div {
      background: from #fff to #000; /* Invalid syntax */
    }
  </style>
</head>
<body>
  <div>Bad background</div>
</body>
</html>

Correct CSS (Gradient):

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Correct CSS Gradient</title>
  <style>
    div {
      background: linear-gradient(to right, #fff, #000);
    }
  </style>
</head>
<body>
  <div>Good background</div>
</body>
</html>

Correct CSS (Solid Color):

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Correct CSS Color</title>
  <style>
    div {
      background: #fff;
    }
  </style>
</head>
<body>
  <div>White background</div>
</body>
</html>

Always use a valid color value or gradient function for the background property.

CSS: “background”: The first argument to the “linear-gradient” function should be “to top”, not “top”.

Use the correct direction keyword syntax in CSS gradients: replace top with to top.

In CSS Images Level 4, the first argument of linear-gradient() should either be an angle (e.g., 180deg) or a direction using the to keyword (e.g., to top, to right). Older syntax like linear-gradient(top, ...) is no longer valid and triggers validator errors. Valid forms include: linear-gradient(to top, #fff, #000), linear-gradient(180deg, #fff, #000), or simply omit the direction to default to to bottom. Keep gradients in your CSS, not HTML attributes. The style attribute or a stylesheet can set the background or background-image with a valid gradient function.

HTML Examples

Example showing the issue

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Gradient Issue</title>
    <style>
      .box {
        width: 200px;
        height: 100px;
        background: linear-gradient(top, #ffffff, #000000); /* invalid */
      }
    </style>
  </head>
  <body>
    <div class="box"></div>
  </body>
</html>

Fixed example (valid syntax)

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Gradient Fixed</title>
    <style>
      .box {
        width: 200px;
        height: 100px;
        /* Option A: direction keyword */
        background: linear-gradient(to top, #ffffff, #000000);
        /* Option B: angle (equivalent) */
        /* background: linear-gradient(0deg, #ffffff, #000000); */
      }
    </style>
  </head>
  <body>
    <div class="box"></div>
  </body>
</html>

CSS: “background”: X is not a “background-color” value.

There’s an invalid value for the background property in your CSS. The W3C HTML Validator has attempted to match the value to a background color, without success.

Here’s how to resolve this issue:

Identify the Correct CSS Configuration: The background property in CSS can take various forms, such as a color, an image, or a combination of background components. Ensure you provide a valid value.
Correct the Value: If you meant to set a background color, use a valid color format (e.g., hexadecimal, RGB, RGBA, named color, etc.).

Valid CSS Examples:

Using a named color:
```
.example {
  background: blue;
}
```
Using a hexadecimal color:
```
.example {
  background: #00ff00;
}
```

Using an RGB color:

.example {
  background: rgb(255, 0, 0);
}

Using an RGBA color (with transparency):

.example {
  background: rgba(255, 0, 0, 0.5);
}

Setting an image as background:

.example {
  background: url('image.jpg');
}

Combining multiple background properties:

.example {
  background: url('image.jpg') no-repeat center/cover;
}