# Decorations, fonts, and color

```latex
\hat{x},\ \bar{x},\ \vec{x},\ \dot{x},\ \ddot{x},\ \widetilde{x},\ \overline{AB},\ \underline{important}
```

```latex
\mathrm{upright}\quad \mathit{italic}\quad \mathbf{bold}\quad \mathsf{sans}\quad \mathtt{mono}\quad \mathcal{F}\quad \mathbb{R}
```

```latex
\color{royalblue}{a^2+b^2}\color{black}{=}\color{crimson}{c^2}
```

```latex
\boxed{x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}}
```