I would like to know what calculation I can use in language like javascript , php or python to find the negative of a cor hexadecimal.
Example: If white negative is black, then I assume:
'#FFFFFF => #000000'
Or
0xFFFFFF => 0x000000
The inverse color can be calculated via exclusive OR (XOR) versus the maximum value (#FFFFFF).
The hexadecimal color format is already a hint of how to do this: each of the double octets in #RRGGBB represents a primary color whose intensity can range from # 00 to #FF (255 in decimal).
In other words, each primary color is represented by 8 bits.
To invert a color, reverse the bits:
Cor Valor HEX valor BIN BIN invertido HEX invertido
Preto #000000 B00000000 00000000 00000000 B11111111 11111111 11111111 #FFFFFF
Branco #FFFFFF B11111111 11111111 11111111 B00000000 00000000 00000000 #000000
Azul #0000FF B00000000 00000000 11111111 B11111111 11111111 00000000 #FFFF00
An example code in Angular / javaScript that performs this operation follows:
function SampleController($scope) {
$scope.sourceValue = 0;
$scope.inverseColor = function(){
var srcVal = $scope.sourceValue;
var valNumerico = parseInt(srcVal, 16);
var mascara = parseInt('FFFFFF', 16);
var dest = valNumerico ^ mascara; //Operação XOR
return dest.toString(16);
};
}<html ng-app>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script></head><body><divng-controller="SampleController">
Cor: #<input type='text' ng-model='sourceValue'>
<br />
Inversa: {{ inverseColor() }}
</div>
</body>
</html> I found an example in PHP :
function color_inverse($color){
$color = str_replace('#', '', $color);
if (strlen($color) != 6){ return '000000'; }
$rgb = '';
for ($x=0;$x<3;$x++){
$c = 255 - hexdec(substr($color,(2*$x),2));
$c = ($c < 0) ? 0 : dechex($c);
$rgb .= (strlen($c) < 2) ? '0'.$c : $c;
}
return '#'.$rgb;
}
Testing:
// preto -> branco
print color_inverse('#000000');
// --> retorna #ffffff
Credits: Link
If it's for display only you can solve this in CSS
-webkit-filter: invert(100%);
filter: invert(100%);
Via Javascript has the solution in this other question. link