UITextfield borderColor and width on one side of the text field

I have a text field setup like so:

textField.borderStyle = UITextBorderStyleLine;
textField.layer.borderColor = [[UIColor greenColor] CGColor];
textField.layer.borderWidth= 10.0f;'

But is it possible to just have a larger border on the left side and it be a different color? Or do I have to position a drawRect there with the color I want and position?

try with this code might be help's you add Border left side of custom TextFiled like Bellow:-

- (void)viewDidLoad
{

    [super viewDidLoad];
    UIView *bottomBorder = [[UIView alloc]
                            initWithFrame:CGRectMake(0,0,4,txtField.frame.size.height)];
    bottomBorder.backgroundColor = [UIColor redColor];
    [txtField addSubview:bottomBorder];

}

This Bellow delegate Code for start after some space in textfield

- (void)textFieldDidBeginEditing:(UITextField *)textField {
    UIView *paddingView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 5, 20)];
    textField.leftView = paddingView;
    textField.leftViewMode = UITextFieldViewModeAlways;
}

OUTPUT look like this:-