how to add custom color to flutter?

Question

I want to change the color of AppBar and use a custom color for it, I tried many options but none seem to work. Is there anything I'm missing?

import 'package:flutter/material.dart';

final ThemeData CompanyThemeData = new ThemeData(
  brightness: Brightness.light,
  primaryColorBrightness: Brightness.light,
  accentColor: CompanyColors.black[500],
  accentColorBrightness: Brightness.light
);
  
class CompanyColors {
  CompanyColors._(); // this basically makes it so you can instantiate this class
 
 static const _blackPrimaryValue = 0xFF000000;

  static const MaterialColor black = const MaterialColor(
    _blackPrimaryValue,
    const <int, Color>{
      50:  const Color(0xFFe0e0e0),
      100: const Color(0xFFb3b3b3),
      200: const Color(0xFF808080),
      300: const Color(0xFF4d4d4d),
      400: const Color(0xFF262626),
      500: const Color(_blackPrimaryValue),
      600: const Color(0xFF000000),
      700: const Color(0xFF000000),
      800: const Color(0xFF000000),
      900: const Color(0xFF000000),
    },
  );
}

and then I have used it in main.dart as

Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      theme: new ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or press Run > Flutter Hot Reload in IntelliJ). Notice that the
        // counter didn't reset back to zero; the application is not restarted.
        primarySwatch:Theme1.CompanyColors.black[50],
      ),
      home: new MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }

but after execution it says

type Color is not of subtype MaterialColor

Answer 1

basically flutter uses color AARRGGBB format you can use below color code with any color property like:

new Container(color: const Color(0xff2980b9));

AA = transparency

RR = red

GG = green

BB = blue

now if you want to create custom color 8-digit code from 6-digit color code then just append transparency (AA) value to it

Transparency percentages Following are some example transparency percentages and their hex values

100% - FF
95% - F2
90% - E6
85% - D9
80% - CC
75% - BF
70% - B3
65% - A6
60% - 99
55% - 8C
50% - 80
45% - 73
40% - 66
35% - 59
30% - 4D
25% - 40
20% - 33
15% - 26
10% - 1A
5% - 0D
0% - 00

in my case i always use AA = ff because 6-digit color has ff transparency. for 6-digit color best site