UINavigationBar background color setted from storyboard differ from the color setted by code - ios

Question

My app will be available only for iOS 8 and I'm working with XCode 6.1.1.
If I set the color through the storyboard (setting theBar Tint attribute on Navigation Bar section)
The desired color is:
56 186 145
I used Core coding utilities to get the floating values of my color.
By code:
let backgroundColor = UIColor(red: 0.22, green: 0.729, blue: 0.569, alpha: 1.0)
self.navigationController!.navigationBar.barTintColor = backgroundColor
self.navigationController!.navigationBar.translucent = false
Color setted through storyboard is the same as the Original RGB.
By code:
By storyboard:
EDIT
I tried using let backgroundColor = UIColor(red: 0.255, green: 0.769, blue: 0.635, alpha: 1.0) and rgb from storyboard: 65 196 162 based on #siejkowski comment, but I get these colors:
By code:
By storyboard:
Why?

Answer 1

There is two reason for the color differences here you observed.
The value set in Storyboard is RGB (sRGB IEC61966-2.1) type and when you code UIColor by RGB value it will return RGB (Generic RGB) values.
So when you change color from Storyboard the values are different for RBG types. To get exact RGB value change type of RGB Sliders in Storyboard.
Click on Settings icon which is exactly right to the RGB Sliders Option. It will show a pop-up menu - select Generic RGB option.
Now you can observe an image that values for RGB
56 186 145
is now change to
49 175 126
So these are desire values to code.
Roundup issue:
In code, you are passing giving round up values for parameter like in below line
UIColor(red: 0.22, green: 0.729, blue: 0.569, alpha: 1.0)
So it will make a small change per pixel of the color code. I suggest you divide this values by 255 and leave round up calculation for the compiler. Which will gives you desire color accuracy.
So now for new values update code will be:
let backgroundColor = UIColor(red: 49.0/255.0, green: 175.0/255.0, blue: 126.0/255.0, alpha: 1.0)
self.navigationController!.navigationBar.barTintColor = backgroundColor
self.navigationController!.navigationBar.isTranslucent = false

Answer 2

You see the difference in colors because they are set using the same RGB values, but in different color-spaces.
UIColor, when set from code, interprets the values as from sRGB space, as provided here: https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CGColorSpace/index.html
However, it seems that the Storyboard color picker is using native values RGB by default. You need to convert between the two. You can do it in Storyboard color picker by clicking the settings icon next to RGB Sliders list picker in Colors tab. Native RGB values are set under Color LCD setting and sRGB values are under sRGB, of course.
When you do it, is seems that 56 186 145 in native RGB space is 73 186 141 in sRGB space. So your code needs to be:
let backgroundColor = UIColor(red: 0.286, green:0.729, blue:0.553, alpha:1.0)

Answer 3

When I try to change the color space to GenericRGB from the storyboard/Interface builder (on XCode 6.3.2), XCode does not save the change. So if I reopen the color from Interface builder the color space is always sRGBIEC61966-2.1.
So I came up a different solution that may be useful for someone else:
with the Mac OS default app "ColorSync Utility" I used the Calculator and translate the value of my color from GenericRGB to a sRGBIEC61966-2.1. Then I set the translated value into the Interface builder and I obtained the same result as was obtaining it programmatically!