HTML5怎么选择颜色
在HTML5中，我们可以使用CSS(层叠样式表)来选择颜色，CSS提供了丰富的颜色选择器，可以帮助我们轻松地为网页添加各种颜色，本文将详细介绍如何使用CSS选择器来选择颜色，并提供一些常见的颜色选择技巧。
RGB和HEX颜色值
1、1 RGB颜色值
RGB(红绿蓝)是一种用于表示颜色的数学模型，它由三个整数值组成，分别表示红、绿、蓝三种基色的强度，每个值的范围是0到255,其中0表示完全没有该颜色，而255表示该颜色的最大强度，红色可以表示为(255, 0, 0),绿色为(0, 255, 0),蓝色为(0, 0, 255)。
在HTML5中，我们可以使用RGB颜色值来设置元素的颜色。
<!DOCTYPE html>
<html>
<head>
<style>
p {
color: rgb(255, 0, 0);
}
</style>
</head>
<body>
<p>这段文字将显示为红色。</p>
</body>
</html>
1、2 HEX颜色值
HEX(十六进制)是一种用于表示颜色的字符串格式，它以“”开头，后跟6个十六进制数字(0-9或A-F),每两个数字之间用一个短横线分隔，红色可以表示为FF0000,绿色为00FF00,蓝色为0000FF。
在HTML5中，我们可以使用HEX颜色值来设置元素的颜色。
<!DOCTYPE html>
<html>
<head>
<style>
p {
color: FF0000;
}
</style>
</head>
<body>
<p>这段文字将显示为红色。</p>
</body>
</html>
HSL和HSLA颜色值
2、1 HSL颜色值
HSL(色相、饱和度、亮度)是一种用于表示颜色的数学模型，它与RGB模型类似，但使用了不同的命名约定，HSL中的色相表示颜色的基本属性，饱和度表示颜色的纯度，亮度表示颜色的明暗程度，HSL中的值范围也是0到360、0%到100%、0%到100%，红色可以表示为(0, 100%, 50%),绿色为(120, 100%, 50%),蓝色为(240, 100%, 50%)。
在HTML5中，我们可以使用HSL颜色值来设置元素的颜色，需要注意的是，HSL颜色值需要转换为RGB颜色值才能应用到元素上，转换方法如下：
function hslToRgb(h, s, l) {
let r, g, b;
if (s === 0) {
r = g = b = l; // achromatic
} else {
const hue2rgb = (p, q, t) => {
if (t < 0) t += 1;
if (t > 1) t -= 1;
if (t < 1/6) return p + (q p) * 6 * t;
if (t < 1/2) return q;
if (t < 2/3) return p + (q p) * (2/3 t) * 6;
return p;
}
const q = l < 0.5 ? l * (1 + s) : l + s l * s;
const p = 2 * l q;
r = hue2rgb(p, q, h + 1/3);
g = hue2rgb(p, q, h);
b = hue2rgb(p, q, h 1/3);
}
return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)]; // RGB values between [0,255] are returned as integers. If you want them in floating point format instead of integers you can modify the function like this: return [r *= r > g && g > b? r > g+b? "ff" + r: "pp" + p: "qq" + q, g *= g > r && r > b? g > r+b? "ff" + g: "pp" + p: "qq" + q, b *= b > g && g > r? b > g+r? "ff" + b: "pp" + p: "qq" + q]; // See https://stackoverflow.com/a/4783838 for more info on how to convert RGB values to hexadecimal format. // The above function will return an array with three elements in the form of strings such as ["ff", "aa", "cc"] or ["ff", "aa", "cc"] depending on whether you want to use integer or floating point numbers. So you can use it like this: document.body.style.backgroundColor = "rgb(" + [r >> i & j | k << i & ~j | l >> i & ~k & j].join(",") + ")"; where i, j, and k are bits that represent the red, green and blue channels respectively. For example, if you want to set the background color to a semi-transparent red with an opacity of half (i.e., the red channel is set to half while the other two channels are set to zero), you can do it like this: document.body.style.backgroundColor = "rgba(" + [r >> i & j | k << i & ~j | l >> i & ~k & j].join(",") + ")"; where i, j, and k are bits that represent the red, green and blue channels respectively. You can find more details about these functions in the MDN Web Docs page on bitwise operations. // This function is based on the implementation of the following JavaScript function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/floor which is used to round down a number to the nearest integer. // This function is based on the implementation of the following JavaScript function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/ceil which is used to round up a number to the nearest integer. // This function is based on the implementation of the following JavaScript function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/min which is used to find the minimum of two or more numbers. // This function is based on the implementation of the following JavaScript function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/max which is used to find the maximum of two or more numbers. // This function is based on the implementation of the following JavaScript function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/abs which returns the absolute value of a number. // This function is based on the implementation of the following JavaScript function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseInt which parses a string argument and returns an integer of specified base (the script represents an integer in decimal base). If no second argument is given then it defaults to JavaScript's standard numeric base of ten (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/NumberBaseNumber). // This function is based on the implementation of the following JavaScript function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseFloat which parses a string argument and returns a floating point number of specified base (the script represents a floating point number in decimal base). If no second argument is given then it defaults to JavaScript's standard numeric base of ten (https://developer.mozilla.org/en-US/docs/Web/JavaScript
原创文章，作者：K-seo，如若转载，请注明出处：https://www.kdun.cn/ask/225600.html
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