How do I update a Custom Category (UIColor) in iOS?

Question

I have created a custom class of UIColor so that I can easily update the color throughout my app. And I have a UITableView with various other color settings. I can't figure out how to update the custom color class to my new colors based on the selection.

Thanks for the assistance

EDIT For Clarity:

Custom Class:

+ (UIColor *)NPSBackgroundColor;
+ (UIColor *)NPSPrimaryColor;
+ (UIColor *)NPSSecondaryColor;
+ (UIColor *)NPSAccentColor;


+(UIColor *)NPSBackgroundColor{
return [UIColor colorWithRed: 0.909f green: 0.909f blue: 0.909f alpha:1];
}
+(UIColor *)NPSPrimaryColor{
    return [UIColor colorWithRed: 0.255 green: 0.357 blue: 0.655 alpha: 1];
}
+(UIColor *)NPSSecondaryColor{
    return [UIColor colorWithRed: 0.0f green: 0.0f blue: 0.0f alpha:1];
}
+(UIColor *)NPSAccentColor{
    return [UIColor colorWithRed: 0.0f green: 0.0f blue: 0.0f alpha:1];
}

I want to update the say "primaryColor" when a user taps a button....

Answer 1

Your code is hardcode with specific colors that can't be changed. You need to restructure the code to return variables than can be modified. Something like this:

Your .h:

@interface UIColor (MyColors)

+ (UIColor *)NPSBackgroundColor;
+ (UIColor *)NPSPrimaryColor;
+ (UIColor *)NPSSecondaryColor;
+ (UIColor *)NPSAccentColor;

+ (void)setNPPrimaryColor:(UIColor *)color;

@end

Your .m

#import "UIColor+MyColors.h"

static UIColor *NPSBackgroundColor = nil;
static UIColor *NPSPrimaryColor = nil;
static UIColor *NPSSecondaryColor = nil;
static UIColor *NPSAccentColor = nil;

@implementation UIColor (MyColors)

+(UIColor *)NPSBackgroundColor{
    if (!NPSBackgroundColor) {
        NPSBackgroundColor = [UIColor colorWithRed: 0.909f green: 0.909f blue: 0.909f alpha:1];
    }

    return NPSBackgroundColor;
}

+(UIColor *)NPSPrimaryColor{
    if (!NPSPrimaryColor) {
        return [UIColor colorWithRed: 0.255 green: 0.357 blue: 0.655 alpha: 1];
    }

    return NPSPrimaryColor;
}

+(UIColor *)NPSSecondaryColor{
    if (!NPSSecondaryColor) {
        return [UIColor colorWithRed: 0.0f green: 0.0f blue: 0.0f alpha:1];
    }

    return NPSSecondaryColor;
}

+(UIColor *)NPSAccentColor{
    if (!NPSAccentColor) {
         return [UIColor colorWithRed: 0.0f green: 0.0f blue: 0.0f alpha:1];
    }

    return NPSAccentColor;
}

+ (void)setNPSPrimaryColor:(UIColor)color {
    NPSPrimaryColor = color;
}

@end

Feel free to add the other setters.