Which of the following Color Format is a CSS’s six-digit hexadecimal format is

Which of the following Color Format is a CSS’s six-digit hexadecimal format is the same as color defined in (X)HTML?

2) Which of the following Selector same as :firstline; changed under CSS3 to make pseudoelements obvious?

3) Which of the following Selector selects an element if it’s the only child of its parent with its type?

4) Which of the following Color Format are a 17 defined colors under CSS 2.1?

5) Which of the following Color Format is a CSS colors can also be defined using the keyword rgb, followed by three numbers between 0 and 255, contained in parentheses and separated by commas, with no spaces between them?