$\normalsize{\textsf{*You can use Tex to produce colors, but the real objective of it is to write math so it is more of a workaround that works perfectly.}}$

$\color{#58A6FF}\textsf{\largeⓘ\kern{0.2cm}\normalsize Note}$ Somethings are different here on gist and on the actual markdown of README's on github or the markdown of issues, etc.

• Warnings & Notes
• Learn Tex basic syntax
  $\to$ Font Styles
  $\to$ Colors
  $\to$ Font Sizes
• Color examples table
• Useful links

To do the warning and note on the github markdown is that way:

__Warning__
__Note__

Warning Note

On the gist markdown you need to use the Tex syntax this way:

$\color{#D29922}\textsf{\Large\⚠\kern{0.2cm}\normalsize Warning}$ 
$\color{#58A6FF}\textsf{\Large\ⓘ\kern{0.2cm}\normalsize Note}$

$\color{#D29922}\textsf{\Large⚠\kern{0.2cm}\normalsize Warning}$ $\color{#58A6FF}\textsf{\Largeⓘ\kern{0.2cm}\normalsize Note}$

To learn the syntax of Tex you can look at the Katex docs, you can also check the sorted docs.

Katex are not exacly Tex, but their docs are very well made and easy to understand, also most features of one are in the other. And the syntax is the same.

To start writting with Tex syntax you need to use $ at the start and end of the text. $foo$.

$foo$

If you want to centralize you can put 2 $. $$foo$$ is a centralized text.

$$foo$$

But as you can see the text isn't sans-serif by default and is unreadable if you don't use the \text{foo} to write your text.

$lorem ipsum dolor sit amet$ <- Without \text{}

$\text{ lorem ipsum dolor sit amet}$ <- With \text{}

To change the font style you need to add suffixes to the \text.

To use colors you can use \color or \textcolor.
You can also use background colors with \colorbox or \fcolorbox if you also want a color border (fcolorbox uses 2 params {}).

• MathJax Github
• Github Markup request colors thread (issue 1440)
• LaTex Wiki
• KaTex Wiki
• The TeX Users Group (TUG)