You can use below code:
// To set colour of text
NSDictionary *attributes = [NSDictionary dictionaryWithObject:[UIColor whiteColor] forKey:UITextAttributeTextColor];
[segmentedControl setTitleTextAttributes:attributes forState:UIControlStateNormal];
NSDictionary *highlightedAttributes = [NSDictionary dictionaryWithObject:[UIColor whiteColor] forKey:UITextAttributeTextColor];
[segmentedControl setTitleTextAttributes:highlightedAttributes forState:UIControlStateHighlighted];
// Change color of selected segment
segmentedControl.segmentedControlStyle = UISegmentedControlStyleBar;
UIColor *newTintColor = [UIColor colorWithRed: 255/255.0 green:100/255.0 blue:100/255.0 alpha:1.0];
segmentedControl.tintColor = newTintColor;
UIColor *newSelectedTintColor = [UIColor clearColor];
[[[segmentedControl subviews] objectAtIndex:0] setTintColor:newSelectedTintColor];
And for seting rounded corners you can use below code:
// Add rounded yellow corner to segmented controll view
[segmentedControl.layer setCornerRadius:4.0f];
[segmentedControl.layer setBorderColor:[UIColor colorWithRed:1.0 green:0.7 blue:0.14 alpha:1.0].CGColor];
[segmentedControl.layer setBorderWidth:1.5f];
[segmentedControl.layer setShadowColor:[UIColor blackColor].CGColor];
[segmentedControl.layer setShadowOpacity:0.8];
[segmentedControl.layer setShadowRadius:3.0];
[segmentedControl.layer setShadowOffset:CGSizeMake(2.0, 2.0)];