Colors

There are many ways to specify the color value. One of the commom way is to use the **Colors** class. This class has defined a lot of constants which you can use to specify a particular color. For example,

Colors.red, Colors.green, Colors.black, etc

You can use some specific index to specify the opacity.

Colors.red[100], Colors.blue[400]

You can use only following indices -

50, 100, 200, 300, 400, 500, 600, 700, 800, 900

The smaller the index, the pale the color become and the greater the index the deeper the color become.

Note that, few colors have only following indices -

100, 200, 400 and 700

For example red, pink color doesn't have 600 index. These color have only above specified indices.

Colors.transparent

The word transparent can be used to specify transparent color which is fully invisible.

Black and White

In the case of black and white color the variation is different. Here are some example,

Colors.black12, Colors.black26, Colors.black38, Colors.black45, Colors.black54, 
Colors.black87, Colors.white10, Colors.white12, Colors.white24, Colors.white30, 
Colors.white38, Colors.white54, Colors.white60, Colors.white70

Colors.black12 means black color with 12% opacity. Colors.white60 means white color with 60% opacity.

If you use just black or white, it means they are fully opaque.

Color.RGBO()

The word RGBO stands for red, green, blue and Opacity.

Color.fromRGBO(239, 240, 241, 1),