CSS 2.1 Reference: outline Property

CSS outline Property
Syntax	selector {outline: color style width;} color is specified by using a color-value or one of the following keywords: aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive, orange, purple, red, silver, teal, white, yellow, or invert. style is specified by using one of the following keywords: none, dotted, dashed, solid, double, groove, ridge, inset, or outset. width is specified by using a length or one of the following keywords: thin, medium, or thick. color, style, and width are all OPTIONAL but at least one of them must occur. (OR) selector {outline: value;} value is specified by using the keyword inherit.
Usage	The outline property is used as a shorthand method to specify the following 3 outline properties all in one place. outline-color outline-style outline-width CSS Example: The outline property is set by specifying all 3 values. h1 {outline: red solid thin;}
Keywords	color keywords: aqua - aqua = #00ffff = rgb(0,255,255) black - black = #000000 = rgb(0,0,0) blue - blue = #0000ff = rgb(0,0,255) fuchsia - fuchsia = #ff00ff = rgb(255,0,255) gray - gray = #808080 = rgb(128,128,128) green - green = #008000 = rgb(0,128,0) lime - lime = #00ff00 = rgb(0,255,0) maroon - maroon = #800000 = rgb(128,0,0) navy - navy = #000080 = rgb(0,0,128) olive - olive = #808000 = rgb(128,128,0) orange - orange = #ffa500 = rgb(255,165,0) purple - purple = #800080 = rgb(128,0,128) red - red = #ff0000 = rgb(255,0,0) silver - silver = #c0c0c0 = rgb(192,192,192) teal - teal = #008080 = rgb(0,128,128) white - white = #ffffff = rgb(255,255,255) yellow - yellow = #ffff00 = rgb(255,255,0) invert - Invert the color. style keywords: none - No border. dotted - This is a sample dashed - This is a sample solid - This is a sample double - This is a sample groove - This is a sample ridge - This is a sample inset - This is a sample outset - This is a sample Note: The outline style samples, shown above, may not appear identically in all browsers. width keywords: thin medium thick inherit - A single inherit keyword is used to specify that the values for this property should be taken from the parent element. If inherit is used with the root element, then the initial values for this property will be used. When the inherit keyword is used, no other property values are allowed.
Applies To	All elements
Inherited	No
Initial Value	invert for outline-color none for outline-style medium for outline-width

outline Property Examples
The outline property is set by specifying all 3 values.