The color.darker() function of D3.js is used to make a copy of the color with some extra darkness or brightness in the original color.
Syntax:
color.darker(k)
Parameter: It takes the following parameters:
- k: Here âkâ is the amount of darkness required in the original color. It is the Integer value.
Return values: It returns the object.
Example 1:
When the value of k is not given
<!DOCTYPE html> < html lang = "en" > < head >   < meta charset = "UTF-8" >   < meta name = "viewport"          content=" width = device -width,         initial-scale = 1 .0">   < title >Document</ title > </ head > < style >   .originalColor{     height: 100px;     width: 100px;   }   .darkerColor{     height: 100px;     width: 100px;   } </ style > < body >   Color without color.darker() property   < div class = "originalColor" >     </ div >   Color with color.darker() property   < div class = "darkerColor" >     </ div >   <!--fetching from CDN of D3.js -->   < script type = "text/javascript"    </ script >   < script >     let originalColor=            document.querySelector(".originalColor");     let darkerColor=            document.querySelector(".darkerColor");       var color= d3.color("green");     originalColor.style.backgroundColor=            `rgb(${color.r}, ${color.g}, ${color.b})`;     var color=color.darker()     darkerColor.style.backgroundColor=           `rgb(${color.r}, ${color.g}, ${color.b})`;   </ script > </ body > </ html > |
Output:
Example 2:
When the value of k > 0
<!DOCTYPE html> < html lang = "en" > < head >   < meta charset = "UTF-8" >   < meta name = "viewport"          content=" width = device -width,                  initial-scale = 1 .0">   < title >Document</ title > </ head > < style >   .originalColor{     height: 100px;     width: 100px;   }   .darkerColor{     height: 100px;     width: 100px;   } </ style > < body >   Color without color.darker() property   < div class = "originalColor" >     </ div >   Color with color.darker(2) property   < div class = "darkerColor" >     </ div >   <!--fetching from CDN of D3.js -->   < script type = "text/javascript"    </ script >   < script >     let originalColor= document.querySelector(".originalColor");     let darkerColor= document.querySelector(".darkerColor");     var color= d3.color("green");     originalColor.style.backgroundColor= `rgb(${color.r}, ${color.g}, ${color.b})`;     var color=color.darker(2)     darkerColor.style.backgroundColor= `rgb(${color.r}, ${color.g}, ${color.b})`;   </ script > </ body > </ html > |
Output:
Example 3:
When value of k<0
<!DOCTYPE html> < html lang = "en" > < head >   < meta charset = "UTF-8" >   < meta name = "viewport"          content=" width = device -width,                  initial-scale = 1 .0">   < title >Document</ title > </ head > < style >   .originalColor{     height: 100px;     width: 100px;   }   .darkerColor{     height: 100px;     width: 100px;   } </ style > < body >   Color without color.darker() property   < div class = "originalColor" >     </ div >   Color with color.darker(-2) property   < div class = "darkerColor" >     </ div >   <!--fetching from CDN of D3.js -->   < script type = "text/javascript"    </ script >   < script >     let originalColor= document.querySelector(".originalColor");     let darkerColor= document.querySelector(".darkerColor");     var color= d3.color("green");     originalColor.style.backgroundColor= `rgb(${color.r}, ${color.g}, ${color.b})`;     var color=color.darker(-2)     darkerColor.style.backgroundColor= `rgb(${color.r}, ${color.g}, ${color.b})`;   </ script > </ body > </ html > |
Output: