Validation_Enum

public enum Colors {
    RED,
    ORANGE,
    GREEN,
    BLUE,
}

public Paint(String color) {
        this.setColor(color);
}

public void setColor(String color) {
        if (isValidColor(color)) {
            this.color = color;
        } else {
            throw new IllegalArgumentException("Invalid color");
        }
}

private boolean isValidColor(String color) {
        try {
            Colors.valueOf(color);
            return true;
        } catch (Exception e) {
            return false;
        }
}