Delphi: Method 'Create' hides virtual method of base - but it's right there

Two solutions:

type
  TFruit = class(TObject)
  public
    constructor Create(Color: TColor); virtual;
  end;

  TApple = class(TFruit)
  public
    constructor Create(); reintroduce; overload;
    constructor Create(Color: TColor); overload; override;
  end;

Or:

type
  TFruit = class(TObject)
  public
    constructor Create; overload; virtual; abstract;
    constructor Create(Color: TColor); overload; virtual;
  end;

  TApple = class(TFruit)
  public
    constructor Create(); override;
    constructor Create(Color: TColor); override; 
  end;

This appears to be a "which came first" sort of issue. (It appears NGLN found a solution.)

There's another solution, also. You can use a default parameter:

interface

type
  TFruit=class(TObject)
  public
    constructor Create(Color: TColor); virtual;
  end;

  TApple=class(TFruit)
  public
    constructor Create(Color: TColor = clRed); override;
  end;

implementation

{ TFruit }

constructor TFruit.Create(Color: TColor);
begin
  inherited Create;
end;

{ TApple }

constructor TApple.Create(Color: TColor);
begin
  inherited;
end;

// Test code
var
  AppleOne, AppleTwo: TApple;
begin
  AppleOne := TApple.Create;
  AppleTwo := TApple.Create(clGreen);
end;