The FromArgb method allows you to specify the alpha channel; the FromRgb method uses a default value of 1 for the alpha channel.
The alpha channel of a color determines the amount of transparency of the color. An alpha value of 1 indicates that the color is completely opaque, and a value of 0 indicates that the color is completely transparent.
The sRGB channels (A, R, G, B) and the ScRGB channels (ScA, ScR, ScG, ScB) of the Color structure are synchronized properties. For example, when R, the sRGB red channel, is modified the ScRGB red channel, ScR, is transformed to the equivalent value.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)