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HTML 

              
                <div id="tone_container">
  <img id="tone_image" src="" alt="Background" data-valid="false" />
  <div id="tone_gray" class="tone"></div>
  <div id="tone_minus" class="tone"></div>
  <div id="tone_add" class="tone"></div>
</div>

<div class="controls">
  <ul id="tone_change">
    <li>
      <label for="input_tone_red">
        <span class="color icon name" id="name_tone_red">Red:</span>
        <input type="number" value="0" min="-255" max="255" id="input_tone_red" class="input_tone" oninput="tone_check()" />
      </label>
    </li>
    <li>
      <label for="input_tone_green">
        <span class="color icon name" id="name_tone_green">Green:</span>
        <input type="number" value="0" min="-255" max="255" id="input_tone_green" class="input_tone" oninput="tone_check()" />
      </label>
    </li>
    <li>
      <label for="input_tone_blue">
        <span class="color icon name" id="name_tone_blue">Blue:</span>
        <input type="number" value="0" min="-255" max="255" id="input_tone_blue" class="input_tone" oninput="tone_check()" />
      </label>
    </li>
    <li>
      <label for="input_tone_gray">
        <span class="color icon name" id="name_tone_gray">Gray:</span>
        <input type="number" value="0" min="0" max="255" id="input_tone_gray" class="input_tone" oninput="tone_check()" />
      </label>
    </li>
  </ul>
  <ul id="background_change">
    <li>
      <label for="input_bg_url">
        <span class="icon name">Background URL:</span>
        <input type="text" size="20" value="http://" id="input_bg_url" data-input="false" onblur="url_blurred();" onfocus="url_focused();" oninput="url_check(this.value)" />
      </label>
    </li>
  </ul>
</div>
!

CSS 

              
                #tone_container {
  border: 1px solid #000;
  position: relative;
  display: inline-block;
  margin-bottom: 64px;
}
.tone {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
}
#tone_gray {
  background: rgb(255, 255, 255);
  mix-blend-mode: hue;
  opacity: 0;
}
#tone_minus {
  background: rgb(255, 255, 255);
  mix-blend-mode: multiply;
}
#tone_add {
  background: rgb(0, 0, 0);
  mix-blend-mode: screen;
}

/* Presentational stuff */
#tone_container img {
  display: inline;
  height: auto;
  width: auto;
  font-family: "Helvetica Neue", "Helvetica", Arial, sans-serif;
  vertical-align: top;
}
#tone_container img[data-valid="false"] {
  background: #ccc;
  background: linear-gradient(to top, #000, rgba(128, 128, 128, 0), #fff), linear-gradient(to right, #f00, #ff0, #0f0, #0ff, #00f, #f0f, #f00);
  display: inline-block;
  width: 320px;
  height: 240px;
  font-size: 0;
  position: relative;
}
#tone_container img[data-valid="false"]:after {
  background: rgba(0, 0, 0, 0.8);
  color: #fff;
  content: "Invalid image";
  font-size: 20px;
  position: absolute;
  top: 0;
  left: 0;
  margin: 8px 8px;
  padding: 4px 12px;
}
.controls {
  background: rgba(0, 0, 0, 0.8);
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: 0 -1px 0 #000;
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%; 
}
.controls ul {
  padding: 0;
  margin: 0;
}
.controls li {
  padding: 2px 8px;
  display: inline-block;
}
.controls .name {
  display: inline-block;
  cursor: pointer;
  margin-right: 8px;
  vertical-align: top;
}
.controls .icon {
  color: transparent;
  font-size: 0;
  overflow: hidden;
  height: 16px;
  width: 16px;
}
.controls .color {
  background-image: linear-gradient(to top, rgba(0, 0, 0, 0), #000);
  border: 1px solid #fff;
  box-shadow: 0 0 0 1px #000, inset 0 0 0 1px #000;
  border-radius: 32px;
}
#name_tone_red { background-color: #f00; }
#name_tone_green { background-color: #0f0; }
#name_tone_blue { background-color: #00f; }
#name_tone_gray { background-color: gray; }
.input_tone { width: 64px; vertical-align: top; }

#background_change .icon {
  background: linear-gradient(to right, #f00, #ff0, #0f0, #0ff, #00f, #f0f, #f00);
  border: 1px solid #fff;
  border-radius: 2px;
  box-shadow: 0 0 0 1px #000, inset 0 0 0 1px rgba(0, 0, 0, 0.6);
}
!

JS 

              
                var tone = { red: 0, green: 0, blue: 0, gray: 0 }
var colors_add = { red: 0, green: 0, blue: 0 }
var colors_sub = { red: 255, green: 255, blue: 255 }
var colors_gray = 0

function tone_check() {
  tone.red = tone_input_check(document.getElementById('input_tone_red').value);
  tone.green = tone_input_check(document.getElementById('input_tone_green').value);
  tone.blue = tone_input_check(document.getElementById('input_tone_blue').value);
  tone.gray = tone_input_check_gray(document.getElementById('input_tone_gray').value);
  document.getElementById('input_tone_gray').value = tone.gray;
  tone_calculate(tone.red, tone.green, tone.blue, tone.gray);
  tone_adjust_background();
}

function tone_input_check(value) {
  if (value > 255) {
    return 255
  } else if (value < -255) {
    return -255
  } else if (value => -255 && value <= 255) {
    return value
  } else {
    return "-"
  }
}
function tone_input_check_gray(value) {
  if (parseInt(value) > 255) {
    return 255
  } else if (parseInt(value) < 0) {
    return 0
  } else {
    return value
  }
}

function tone_calculate(val_red, val_green, val_blue, val_gray) {
	val_red = tone_calculate_value(val_red)
	val_green = tone_calculate_value(val_green)
	val_blue = tone_calculate_value(val_blue)
	val_gray = tone_calculate_gray(val_gray)
	colors_add.red 	= val_red.add;
	colors_add.green = val_green.add;
	colors_add.blue 	= val_blue.add;
	colors_sub.red = val_red.sub;
	colors_sub.green = val_green.sub;
	colors_sub.blue = val_blue.sub;
	colors_gray = val_gray;
}

function tone_calculate_value(value) {
	ary = {sub: 0, add: 0};
	if (parseInt(value) < 0) {
		ary.sub = (255 + parseInt(value));
		ary.add = 0;
	} else if (parseInt(value) >= 0) {
		ary.sub = 255;
		ary.add = parseInt(value);
	}
	return ary
}
function tone_calculate_gray(value) { return ((100 / 255) * 0.01) * value }

function tone_adjust_background() {
	document.getElementById("tone_gray").style.opacity = colors_gray;
  document.getElementById("tone_minus").style.backgroundColor = 'rgb(' + colors_sub.red + ',' + colors_sub.green + ',' + colors_sub.blue + ')';
	document.getElementById("tone_add").style.backgroundColor = 'rgb(' + colors_add.red + ',' + colors_add.green + ',' + colors_add.blue + ')';
}

function url_check(value) {
  e = document.getElementById("input_bg_url")
  i = document.getElementById("tone_image")
  if (e.dataset.input == "true") {
    regex = new RegExp("^(http[s]?:\\/\\/(www\\.)?|ftp:\\/\\/(www\\.)?|www\\.){1}([0-9A-Za-z-\\.@:%_\+~#=]+)+((\\.[a-zA-Z]{2,3})+)(/(.)*)?(\\?(.)*)?");
    if(regex.test(value)){
      // Matches regex
      e.dataset.valid = "true";
      i.dataset.valid = "true";
      i.src = e.value;
    } else {
      // Doesn't match regex
      e.dataset.valid = "false";
      i.dataset.valid = "false";
      i.src = ""
    }
  }
}
function url_focused() {
  e = document.getElementById("input_bg_url");
  if (e.dataset.input == "false") {
    e.dataset.input = "true";
    e.value = "";
	}
}
function url_blurred() {
  e = document.getElementById("input_bg_url");
  if (e.dataset.input == "true" && e.value == "") {
    e.dataset.input = "false";
    e.value = "http://";
	}
}
!
999px

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