ObjectiveC - UIButton remains highlighted/selected and background color and font color changes when highlighted/selected

I have used the interface builder to create the following UIButton for different time slot and a UIButton for Search. I want the UIButton for different time slot to remain selected/highlighted when user tap on it. And the background color and font color will change as well (See pic for illustration). Moreover, user can only select one of the time slot at one time.

UIButton with different time slot

What I am trying to achieve button

Code

#import "Search.h"
#import <QuartzCore/QuartzCore.h>

@interface Search(){

}

@end

@implementation Search

@synthesize btn1;
@synthesize btn2;
@synthesize btn3;
@synthesize btn4;
@synthesize btn5;
@synthesize btn6;
@synthesize btn7;
@synthesize btn8;
@synthesize btn9;
@synthesize btnSearch;

- (void)viewDidLoad
{
    [super viewDidLoad];

    _borderBox.layer.shadowRadius  = 5;
    _borderBox.layer.shadowColor   = [UIColor colorWithRed:211.f/255.f green:211.f/255.f blue:211.f/255.f alpha:1.f].CGColor;
    _borderBox.layer.shadowOffset  = CGSizeMake(0.0f, 0.0f);
    _borderBox.layer.shadowOpacity = 0.9f;
    _borderBox.layer.masksToBounds = NO;

    btn1.layer.borderColor = [UIColor lightGrayColor].CGColor;
    btn1.layer.borderWidth =1.0f;
    btn2.layer.borderColor = [UIColor lightGrayColor].CGColor;
    btn2.layer.borderWidth =1.0f;
    btn3.layer.borderColor = [UIColor lightGrayColor].CGColor;
    btn3.layer.borderWidth =1.0f;
    btn4.layer.borderColor = [UIColor lightGrayColor].CGColor;
    btn4.layer.borderWidth =1.0f;
    btn5.layer.borderColor = [UIColor lightGrayColor].CGColor;
    btn5.layer.borderWidth =1.0f;
    btn6.layer.borderColor = [UIColor lightGrayColor].CGColor;
    btn6.layer.borderWidth =1.0f;
    btn7.layer.borderColor = [UIColor lightGrayColor].CGColor;
    btn7.layer.borderWidth =1.0f;
    btn8.layer.borderColor = [UIColor lightGrayColor].CGColor;
    btn8.layer.borderWidth =1.0f;
    btn9.layer.borderColor = [UIColor lightGrayColor].CGColor;
    btn9.layer.borderWidth =1.0f;
}

-(void)viewWillAppear:(BOOL)animated{


}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];

}

+(void)makeButtonColored:(UIButton*)button color1:(UIColor*) color
{

    CALayer *layer = button.layer;
    layer.cornerRadius = 8.0f;
    layer.masksToBounds = YES;
    layer.borderWidth = 4.0f;
    layer.opacity = .3;//
    layer.borderColor = [UIColor colorWithWhite:0.4f alpha:0.2f].CGColor;

    CAGradientLayer *colorLayer = [CAGradientLayer layer];
    colorLayer.cornerRadius = 8.0f;
    colorLayer.frame = button.layer.bounds;
    //set gradient colors
    colorLayer.colors = [NSArray arrayWithObjects:
                     (id) color.CGColor,
                     (id) color.CGColor,
                     nil];

    //set gradient locations
    colorLayer.locations = [NSArray arrayWithObjects:
                        [NSNumber numberWithFloat:0.0f],
                        [NSNumber numberWithFloat:1.0f],
                        nil];


    [button.layer addSublayer:colorLayer];

}

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