How to Use Uicolorfromrgb in Swift

How can I use UIColorFromRGB in Swift?

Here's a Swift version of that function (for getting a UIColor representation of a UInt value):

func UIColorFromRGB(rgbValue: UInt) -> UIColor {
    return UIColor(
        red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
        green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
        blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
        alpha: CGFloat(1.0)
    )
}

view.backgroundColor = UIColorFromRGB(0x209624)

How to initialize UIColor from RGB values properly?

The values are in the 0.0 to 1.0 range.

E.g. divide by 255., but remember the decimal dot so you get floating point division and not integer division.

Like

selectedColor = [UIColor colorWithRed:14.0/255.0 green:114.0/255.0 blue:199.0/255.0 alpha:1];

How to use hex color values

#ffffff are actually 3 color components in hexadecimal notation - red ff, green ff and blue ff. You can write hexadecimal notation in Swift using 0x prefix, e.g 0xFF

To simplify the conversion, let's create an initializer that takes integer (0 - 255) values:

extension UIColor {
   convenience init(red: Int, green: Int, blue: Int) {
       assert(red >= 0 && red <= 255, "Invalid red component")
       assert(green >= 0 && green <= 255, "Invalid green component")
       assert(blue >= 0 && blue <= 255, "Invalid blue component")

       self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: 1.0)
   }

   convenience init(rgb: Int) {
       self.init(
           red: (rgb >> 16) & 0xFF,
           green: (rgb >> 8) & 0xFF,
           blue: rgb & 0xFF
       )
   }
}

Usage:

let color = UIColor(red: 0xFF, green: 0xFF, blue: 0xFF)
let color2 = UIColor(rgb: 0xFFFFFF)

How to get alpha?

Depending on your use case, you can simply use the native UIColor.withAlphaComponent method, e.g.

let semitransparentBlack = UIColor(rgb: 0x000000).withAlphaComponent(0.5)

Or you can add an additional (optional) parameter to the above methods:

convenience init(red: Int, green: Int, blue: Int, a: CGFloat = 1.0) {
    self.init(
        red: CGFloat(red) / 255.0,
        green: CGFloat(green) / 255.0,
        blue: CGFloat(blue) / 255.0,
        alpha: a
    )
}

convenience init(rgb: Int, a: CGFloat = 1.0) {
    self.init(
        red: (rgb >> 16) & 0xFF,
        green: (rgb >> 8) & 0xFF,
        blue: rgb & 0xFF,
        a: a
    )
}

(we cannot name the parameter alpha because of a name collision with the existing initializer).

Called as:

let color = UIColor(red: 0xFF, green: 0xFF, blue: 0xFF, a: 0.5)
let color2 = UIColor(rgb: 0xFFFFFF, a: 0.5)

To get the alpha as an integer 0-255, we can

convenience init(red: Int, green: Int, blue: Int, a: Int = 0xFF) {
    self.init(
        red: CGFloat(red) / 255.0,
        green: CGFloat(green) / 255.0,
        blue: CGFloat(blue) / 255.0,
        alpha: CGFloat(a) / 255.0
    )
}

// let's suppose alpha is the first component (ARGB)
convenience init(argb: Int) {
    self.init(
        red: (argb >> 16) & 0xFF,
        green: (argb >> 8) & 0xFF,
        blue: argb & 0xFF,
        a: (argb >> 24) & 0xFF
    )
}

Called as

let color = UIColor(red: 0xFF, green: 0xFF, blue: 0xFF, a: 0xFF)
let color2 = UIColor(argb: 0xFFFFFFFF)

Or a combination of the previous methods. There is absolutely no need to use strings.

UIColor not working with RGBA values

RGB values for UIColor are between 0 and 1 (see the documentation "specified as a value from 0.0 to 1.0")

You need to divide your numbers by 255:

passwordTextField.textColor = UIColor(red: CGFloat(202.0/255.0), green: CGFloat(228.0/255.0), blue: CGFloat(230.0/255.0), alpha: CGFloat(1.0))

Another thing, you don't need to create CGFloats:

passwordTextField.textColor = UIColor(red:202.0/255.0, green:228.0/255.0, blue:230.0/255.0, alpha:1.0)

How to define a HEX color macro in swift

func HColorToRGB(rgbValue: Int, alpha: Float) -> UIColor {
return UIColor(
    red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
    green: CGFloat((rgbValue & 0xFF00) >> 8) / 255.0,
    blue: CGFloat(rgbValue &0xFF) / 255.0,
    alpha: CGFloat(alpha)
)
}

yourView.backgroundColor = HColorToRGB("passyourValue","alphaValue")

How to pass value through UIColorFromRGB in Objective-C

You are retrieving a NSString object (coloring) but the macro expects an integer.

To get an integer from a hex string you can use NSScanner class.

Along the lines of:

unsigned int hexValue = 0;
NSScanner *scanner = [NSScanner scannerWithString:coloring];
[scanner setScanLocation:0]; // depends on your exact string format you may have to use location 1
[scanner scanHexInt:&hexValue];

shapeLayer.strokeColor = UIColorFromRGB(hexValue).CGColor;

How to use hex color values

#ffffff are actually 3 color components in hexadecimal notation - red ff, green ff and blue ff. You can write hexadecimal notation in Swift using 0x prefix, e.g 0xFF

To simplify the conversion, let's create an initializer that takes integer (0 - 255) values:

extension UIColor {
   convenience init(red: Int, green: Int, blue: Int) {
       assert(red >= 0 && red <= 255, "Invalid red component")
       assert(green >= 0 && green <= 255, "Invalid green component")
       assert(blue >= 0 && blue <= 255, "Invalid blue component")

       self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: 1.0)
   }

   convenience init(rgb: Int) {
       self.init(
           red: (rgb >> 16) & 0xFF,
           green: (rgb >> 8) & 0xFF,
           blue: rgb & 0xFF
       )
   }
}

Usage:

let color = UIColor(red: 0xFF, green: 0xFF, blue: 0xFF)
let color2 = UIColor(rgb: 0xFFFFFF)

How to get alpha?

Depending on your use case, you can simply use the native UIColor.withAlphaComponent method, e.g.

let semitransparentBlack = UIColor(rgb: 0x000000).withAlphaComponent(0.5)

Or you can add an additional (optional) parameter to the above methods:

convenience init(red: Int, green: Int, blue: Int, a: CGFloat = 1.0) {
    self.init(
        red: CGFloat(red) / 255.0,
        green: CGFloat(green) / 255.0,
        blue: CGFloat(blue) / 255.0,
        alpha: a
    )
}

convenience init(rgb: Int, a: CGFloat = 1.0) {
    self.init(
        red: (rgb >> 16) & 0xFF,
        green: (rgb >> 8) & 0xFF,
        blue: rgb & 0xFF,
        a: a
    )
}

(we cannot name the parameter alpha because of a name collision with the existing initializer).

Called as:

let color = UIColor(red: 0xFF, green: 0xFF, blue: 0xFF, a: 0.5)
let color2 = UIColor(rgb: 0xFFFFFF, a: 0.5)

To get the alpha as an integer 0-255, we can

convenience init(red: Int, green: Int, blue: Int, a: Int = 0xFF) {
    self.init(
        red: CGFloat(red) / 255.0,
        green: CGFloat(green) / 255.0,
        blue: CGFloat(blue) / 255.0,
        alpha: CGFloat(a) / 255.0
    )
}

// let's suppose alpha is the first component (ARGB)
convenience init(argb: Int) {
    self.init(
        red: (argb >> 16) & 0xFF,
        green: (argb >> 8) & 0xFF,
        blue: argb & 0xFF,
        a: (argb >> 24) & 0xFF
    )
}

Called as

let color = UIColor(red: 0xFF, green: 0xFF, blue: 0xFF, a: 0xFF)
let color2 = UIColor(argb: 0xFFFFFFFF)

Or a combination of the previous methods. There is absolutely no need to use strings.

Setting custom RGB color in drawing class in Swift

If you want to set the color try this:

var Color = UIColor(red: 200.0/255.0, green: 16.0/255.0, blue: 46.0/255.0, alpha: 1.0)

also a very useful tool/ website for converting the colors into useful Swift code:

https://www.ralfebert.de/snippets/ios/swift-uicolor-picker/

Edit:

self.button.setTitleColor(UIColor(red:0.96, green:0.28, blue:0.28, alpha:1.0), forState: .Normal)

or if you want a cleaner solution:

var myColor = UIColor(red:0.96, green:0.28, blue:0.28, alpha:1.0)
self.button.setTitleColor(myColor, forState: .Normal)

How do I create a UIColor from RGBA?

Your values are incorrect, you need to divide each color value by 255.0.

[UIColor colorWithRed:66.0f/255.0f
                green:79.0f/255.0f
                 blue:91.0f/255.0f
                alpha:1.0f];

The docs state:

+ (UIColor *)colorWithRed:(CGFloat)red
                    green:(CGFloat)green
                     blue:(CGFloat)blue
                    alpha:(CGFloat)alpha

Parameters

red
The red component of the color object, specified as a value from 0.0 to 1.0.

green
The green component of the color object, specified as a value from 0.0 to 1.0.

blue
The blue component of the color object, specified as a value from 0.0 to 1.0.

alpha
The opacity value of the color object, specified as a value from 0.0 to 1.0.

Reference here.

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