Change color, arrow type, thickness and dash type

1. Select the existing line drawing by clicking on it.
2. Once clicked, the default left panel will get replaced with editing options in the form of buttons specific to the line, such as "Change color", "Select arrow type", "Select thickness" and "Select dash type".
3. Click on the "Change color" button. Once clicked, a color picker will appear, displaying the line's current color as its value. Change the color of the line by using that color picker as shown below.
4. Click on the "Select arrow type" button. Once clicked, a menu with three button options will appear: a line with a one-sided arrow, a line with arrows on both sides, and a plain line without arrows. The current arrow type of the line will be highlighted. Select the desired arrow type for the line by clicking on it as shown below.
5. Click on the "Select thickness" button. Once clicked, a menu with five thickness options in descending order will appear as buttons, with the current thickness of the line highlighted. Select the desired thickness for the line by clicking on it as shown below.
   
6. Click on the "Select dash type" button. Once clicked, a menu with three dash type options will appear as buttons, with the current dash type of the line highlighted. Select the desired dash type for the line by clicking on it as shown below.
   

Note: Clicking on any part of the video, other than the drawing itself, will result in the current drawing being deselected, the drawing options being hidden, and the default left-side panel reappearing.