How to initialize UIColor from RGB values properly?

Question

I am working on an iPhone application which uses various colors. When user selects the particular color button I set drawing color accordingly. I am getting the color for some but in the most of the cases I am getting white color.

Here is my code:

-(IBAction)colorSelected:(UIButton *)sender {  switch (sender.tag)  {     case 1:         self.drawcolor= [UIColor colorWithRed:200 green:191 blue:231 alpha:1];         break;                 case 2:         self.drawcolor= [UIColor colorWithRed:163 green:73 blue:164 alpha:1];         break;       case 3:         self.drawcolor= [UIColor colorWithRed:112 green:146 blue:76 alpha:1];         break;       case 4:         self.drawcolor= [UIColor colorWithRed:63 green:72 blue:204 alpha:1];         break;       case 5:         self.drawcolor= [UIColor colorWithRed:153 green:217 blue:234 alpha:1];         break;       case 6:         self.drawcolor= [UIColor colorWithRed:0 green:162 blue:232 alpha:1];         break;               case 7:         self.drawcolor= [UIColor colorWithRed:181 green:230 blue:29 alpha:1];         break;       case 8:         self.drawcolor= [UIColor colorWithRed:34 green:177 blue:76 alpha:1];         break;               case 9:         self.drawcolor= [UIColor colorWithRed:239 green:228 blue:176 alpha:1];         break;               case 10:         self.drawcolor= [UIColor colorWithRed:255 green:201 blue:0 alpha:1];         break;               case 11:         self.drawcolor= [UIColor colorWithRed:255 green:201 blue:14 alpha:1];         break;               case 12:         self.drawcolor= [UIColor colorWithRed:237 green:28 blue:36 alpha:1];         break;               case 13:         self.drawcolor= [UIColor colorWithRed:255 green:127 blue:39 alpha:1];         break;               case 14:         self.drawcolor= [UIColor colorWithRed:255 green:174 blue:201 alpha:1];         break;               case 15:         self.drawcolor= [UIColor colorWithRed:185 green:122 blue:87 alpha:1];         break;               case 16:         self.drawcolor= [UIColor colorWithRed:136 green:0 blue:21 alpha:1];         break;               case 17:         self.drawcolor= [UIColor colorWithRed:195 green:195 blue:195 alpha:1];         break;               case 18:         self.drawcolor= [UIColor colorWithRed:127 green:127 blue:127 alpha:1];         break;               case 19:         self.drawcolor= [UIColor colorWithRed:255 green:255 blue:255 alpha:1];         break;     case 20:         self.drawcolor= [UIColor colorWithRed:0 green:0 blue:0 alpha:1];         break;       default:         break; }  self.preColor=self.drawcolor; self.lineWidth=self.prelineWidth; } 

Can any one tell me what I am doing wrong ? Sumit

Answer 1

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]; 

Answer 2

Pragmatic approach with Swift.

extension UIColor {     convenience init(rgbColorCodeRed red: Int, green: Int, blue: Int, alpha: CGFloat) {       let redPart: CGFloat = CGFloat(red) / 255      let greenPart: CGFloat = CGFloat(green) / 255      let bluePart: CGFloat = CGFloat(blue) / 255       self.init(red: redPart, green: greenPart, blue: bluePart, alpha: alpha)     } }