Use the `bgcolor` attribute in older HTML:
`
`Use inline CSS with the `style` attribute:
`
`Set background color for a specific element:
`
Content
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Use an internal CSS style rule:
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`
Use an external CSS file:
`body { background-color: yellow; }`
Use color names:
`background-color: red;`
Use hexadecimal color codes:
`background-color: #ffcc00;`
Use RGB values:
`background-color: rgb(255, 204, 0);`
Use RGBA values:
`background-color: rgba(255, 204, 0, 0.5);`
