例如：我正在生成一个折线图,该图显示了客户商店的销售业绩.用户将提交商店编号(1-200),并且图表将为每个商店绘制一条线.我需要一个函数,该函数将为每个商店返回一种颜色,并且我希望这些颜色看起来彼此之间显着不同.

我几乎要完成这项工作.

这是一个迭代色调的jsfiddle：
http://jsfiddle.net/cabichandani/ub3H9/5/

var scale = 200;
var hueSkip = 5;

for (var storeNumber = 1; storeNumber < scale; storeNumber++) {
    var h = storeNumber/scale;
    var color = getColor(h);
    var colorString = getColorString(h);
    $("#store-list")
        .append('<li style="background-color:' + 
                colorString + 
                ';">Store: ' + 
                storeNumber + ' hue:' + 
                h.toFixed(3) + ' color:' + 
                colorString + '</li>');
}

function getColorString(hue) {
    var color = getColor(hue);
    return "rgb(" + color[0] + "," + color[1] + "," + color[2] + ")";
}

function getColor(hue) {
    var huePercent = hue * 100;
    var hueSkipAmount = hueSkip * huePercent;
    var newHuePercent = (huePercent + hueSkipAmount) % 100;
    var newHue = newHuePercent / 100;

    return hslToRgb(newHue,1,0.5);
}

/**
 * Converts an HSL color value to RGB. Conversion formula
 * adapted from http://en.wikipedia.org/wiki/HSL_color_space.
 * Assumes h, s, and l are contained in the set [0, 1] and
 * returns r, g, and b in the set [0, 255].
 *
 * @param   Number  h       The hue
 * @param   Number  s       The saturation
 * @param   Number  l       The lightness
 * @return  Array           The RGB representation
 */
function hslToRgb(h, s, l){
    var r, g, b;

    if(s == 0){
        r = g = b = l; // achromatic
    }else{
        function 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;
        }

        var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
        var 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)];
}

/**
 * Converts an RGB color value to HSL. Conversion formula
 * adapted from http://en.wikipedia.org/wiki/HSL_color_space.
 * Assumes r, g, and b are contained in the set [0, 255] and
 * returns h, s, and l in the set [0, 1].
 *
 * @param   Number  r       The red color value
 * @param   Number  g       The green color value
 * @param   Number  b       The blue color value
 * @return  Array           The HSL representation
 */
function rgbToHsl(r, g, b){
    r /= 255, g /= 255, b /= 255;
    var max = Math.max(r, g, b), min = Math.min(r, g, b);
    var h, s, l = (max + min) / 2;

    if(max == min){
        h = s = 0; // achromatic
    }else{
        var d = max - min;
        s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
        switch(max){
            case r: h = (g - b) / d + (g < b ? 6 : 0); break;
            case g: h = (b - r) / d + 2; break;
            case b: h = (r - g) / d + 4; break;
        }
        h /= 6;
    }

    return [h, s, l];
}

我有一个称为“色相跳过”的概念,它试图跳过看起来过于相似的颜色.

将hueSkip设置为5时,我可以将1-6个存储图绘制在一起,并且它们是容易区分的红黄色.但是,如果我将10和11放在同一张图表上,它们看起来几乎像是相同的绿色阴影.

我想改进功能,以显示出更容易区分的颜色,或者完全采用另一种方法.

解决方法:

为了阐明代码,我将调色板创建与其余代码分开,并将此调色板存储在数组中.
这样,您可以分别测试获得不同值的颜色.

下面我通过在0-360范围内散布色相来创建调色板,但我跳过了绿色的一部分,因为所有绿色都很相似.我将饱和度和亮度分别从(90,80)切换为(65,55)两次.您可能需要在3对(饱和度,亮度)之间切换以获取更多更改.

http://jsbin.com/UlOgiSuZ/1/edit?js,output

function createPalette (colorCount) {
  var newPalette = [];
  var hueStep = Math.floor ( 330 / colorCount ) ;
  var hue = 0 ;
  var saturation = 95 ;
  var luminosity =  55 ;
  var greenJump  = false ;
  for ( var colorIndex=0; colorIndex < colorCount; colorIndex++ ) {
    saturation = (colorIndex & 1) ? 90 : 65;
    luminosity = (colorIndex & 1) ? 80 : 55;
    newPalette.push( hslToRgbString (hue ,saturation, luminosity ));
    hue += hueStep ;
    if (!greenJump && hue >100) {
      hue+=30;
      greenJump = true;
    }
  } 
  return newPalette ;   
}

// dummy context2d used for hsl -> rgb conversion
var dummyContext = document.createElement('canvas').getContext('2d');

function hslToRgbString(h,s,l) {
   dummyContext.fillStyle = 'hsl(' + h +',' + s + '%,' + l +'% )' ; 
  return dummyContext.fillStyle ;
}

测试代码：

function drawPalette( palette, context, x, y, w, h ) {
  context.strokeStyle = '#000';
  context.lineWidth = 1 ;
  for (var i = 0; i < palette.length; i++ ) {
    context.fillStyle = palette [i];
    context.fillRect ( x+i*w, y, w,h );
    context.strokeRect ( x+i*w, y, w,h );
  }
}

// draw some palettes to see how they look
var ctx = document.getElementById('colorCanvas').getContext('2d');

var paletteCount = 17;
for (var i=0; i < paletteCount; i++ ) {
  var myPalette = createPalette(i) ;
 drawPalette ( myPalette, ctx, 0, i *24,20, 20 );
}