Keep getting declaration error.

the task states: Add a public constructor to the GoKart.java class that allows the parameter color to be passed in. In the constructor store the argument color in the private color field.

your method looks like this:

public setColor (String color) {
   mColor = color; 
  }

that is a setter method, not a constructor. setter methods set member variables. Constructors are run whenever an object of that class is created. Generally you put code in constructors that needs to be run to set up an object for use (such as setting a member variable to an initial value etc). the task asked you to create a constructor.

in general, constructors look like this:

public ClassName() {
// do stuff
}

so to add a constructor for GoKart that accepts a parameter for the color we would use:

public GoKart(String color) {

}

then inside the method we need to set mColor to the color passed in

public GoKart(String color) {
mColor = color;
}

the full class file should look like this:

public class GoKart {
  private String mColor = "red";

  public GoKart(String color) {
    mColor = color;
  }

  public String getColor() {
    return mColor;
  }
}