HTML Color Codes: Red to Yellow to Green

Question

I would like to come up with as many HEX HTML values to have a smooth color gradient from red to green:

I would like this to be similar to the following: http://ww

Answer 1

Here is a simple, yet dirty, way to generate these colors:

COLORS = [ "FF00%0.2XFF" % x for x in range(0,260,5) ] + [ "FF00FF%0.2X" % x for x in range(250,-1,-5) ]

The color encoding is for Google maps: aabbggrr.

This will give you a list of 103 colors. I removed three and then indexed the list with using a percentage as an integer.

Answer 2

I used this in a php page:

$percent = .....; //whatever the percentage you want to colour

If ($percent <= 50) {
    $red = 255;
    $green = $percent * 5.1;
}

If ($percent >= 50) {
    $green = 255;
    $red = 255 - ($percent - 50) * 5.1;
}

$blue = 0;

Your RGB is then ($red, $green, $blue)

Note: The 5.1 factor dervies from 255/50

Answer 3

Works in Chrome & Safari only

From NiceWebType.com:

<style type="text/css">
    h1 {
        position: relative;
        font-size: 60px;
        line-height: 60px;
        text-shadow: 0px 0px 3px #000;
    }
    h1 a {
        position: absolute;
        top: 0; z-index: 2;
        color: #F00;
        -webkit-mask-image: -webkit-gradient(linear, left center, right center, from(rgba(0,0,0,1)), to(rgba(0,0,0,0)));
    }
    h1:after {
        content: "CSS Text Gradient (Webkit)";
        color: #0F0;
    }
</style>

<h1><a>CSS Text Gradient (Webkit)</a></h1>

Answer 4

On my side, I solved the issue with 2 brushes:

float sweepAngle = 45.0F; // angle you want ...
LinearGradientBrush linGrBrushUp = new LinearGradientBrush(
    new Point(0, 0), new     Point(w, 0),
    Color.FromArgb(255, 0, 255, 0),     // green
    Color.FromArgb(255, 255, 255, 0)    // yellow
);
LinearGradientBrush linGrBrushDown = new LinearGradientBrush(
    new Point(w, 0), new Point(0, 0),
Color.FromArgb(255, 255, 255, 0),   // yellow
Color.FromArgb(255, 255, 0, 0)      // red
);
g.DrawArc( new Pen(linGrBrushUp, 5), x, y, w, h, 180.0F, sweepAngle>180.0F?180.0F:sweepAngle );
g.DrawArc( new Pen(linGrBrushDown, 5), x, y, w, h, 0.0F, sweepAngle>180.0F?sweepAngle-180.0F:0 );

Answer 5

Here is nice looking gradient from green to red

    /* Green - Yellow - Red */
    .gradient_0    {background: #57bb8a;}
    .gradient_5    {background: #63b682;}
    .gradient_10   {background: #73b87e;}
    .gradient_15   {background: #84bb7b;}
    .gradient_20   {background: #94bd77;}
    .gradient_25   {background: #a4c073;}
    .gradient_30   {background: #b0be6e;}
    .gradient_35   {background: #c4c56d;}
    .gradient_40   {background: #d4c86a;}
    .gradient_45   {background: #e2c965;}
    .gradient_50   {background: #f5ce62;}
    .gradient_55   {background: #f3c563;}
    .gradient_60   {background: #e9b861;}
    .gradient_65   {background: #e6ad61;}
    .gradient_70   {background: #ecac67;}
    .gradient_75   {background: #e9a268;}
    .gradient_80   {background: #e79a69;}
    .gradient_85   {background: #e5926b;}
    .gradient_90   {background: #e2886c;}
    .gradient_95   {background: #e0816d;}
    .gradient_100  {background: #dd776e;}

    /* Red - Yellow - Green */
    .anti-gradient_100  {background: #57bb8a;}
    .anti-gradient_95   {background: #63b682;}
    .anti-gradient_90   {background: #73b87e;}
    .anti-gradient_85   {background: #84bb7b;}
    .anti-gradient_80   {background: #94bd77;}
    .anti-gradient_75   {background: #a4c073;}
    .anti-gradient_70   {background: #b0be6e;}
    .anti-gradient_65   {background: #c4c56d;}
    .anti-gradient_60   {background: #d4c86a;}
    .anti-gradient_55   {background: #e2c965;}
    .anti-gradient_50   {background: #f5ce62;}
    .anti-gradient_45   {background: #f3c563;}
    .anti-gradient_40   {background: #e9b861;}
    .anti-gradient_35   {background: #e6ad61;}
    .anti-gradient_30   {background: #ecac67;}
    .anti-gradient_25   {background: #e9a268;}
    .anti-gradient_20   {background: #e79a69;}
    .anti-gradient_15   {background: #e5926b;}
    .anti-gradient_10   {background: #e2886c;}
    .anti-gradient_5    {background: #e0816d;}
    .anti-gradient_0    {background: #dd776e;}

<div class="gradient_0">0</div>
<div class="gradient_5">5</div>
<div class="gradient_10">10</div>
<div class="gradient_15">15</div>
<div class="gradient_20">20</div>
<div class="gradient_25">25</div>
<div class="gradient_30">30</div>
<div class="gradient_35">35</div>
<div class="gradient_40">40</div>
<div class="gradient_45">45</div>
<div class="gradient_50">50</div>
<div class="gradient_55">55</div>
<div class="gradient_60">60</div>
<div class="gradient_65">65</div>
<div class="gradient_70">70</div>
<div class="gradient_75">75</div>
<div class="gradient_80">80</div>
<div class="gradient_85">85</div>
<div class="gradient_90">90</div>
<div class="gradient_95">95</div>
<div class="gradient_100">100</div>

Answer 6

When I had to do this my choice was to switch from hex to rgb code, which seemed more calculation-friendly.

You can read the details here:

http://blog.pathtosharepoint.com/2009/11/02/visualization-calculated-color-gradients/