From 5e05882034f5724edd6939c81522eaf78134e6d9 Mon Sep 17 00:00:00 2001
From: Katia Gatt <k.gatt@student.tudelft.nl>
Date: Fri, 18 Apr 2025 18:59:58 +0200
Subject: [PATCH] update 2

---
 book/syntax_exercises/009.md | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/book/syntax_exercises/009.md b/book/syntax_exercises/009.md
index 4165cb9..6fc9fc2 100644
--- a/book/syntax_exercises/009.md
+++ b/book/syntax_exercises/009.md
@@ -77,6 +77,8 @@ The displacement can be found using the equation $s = v \cdot t$.
 
 11. The TeachBooks template includes the `sphinx-named-colors` extension, which lets you add colours to parts of your equations using LaTeX. Look at the [CSS named colours](https://developer.mozilla.org/en-US/docs/Web/CSS/named-color) to explore the possible colour options.
 
+12. It is also possible to use custom colours! Look [here](https://teachbooks.io/manual/external/Sphinx-Named-Colors/README.html#) for documentation about the TeachBook extension which allows custom colours.
+
 12. Colours are added to equations using `\namedcolour{...}`, replacing `namedcolour` with the colour of choice. Test this out with the examples in the table below:
 
 ::::{list-table}
@@ -94,24 +96,19 @@ The displacement can be found using the equation $s = v \cdot t$.
    * - darkturquoise
      - `\dfrac{\darkturquoise{\partial}f}{\darkturquoise{\partial}x}`
      - $\dfrac{\darkturquoise{\partial}f}{\darkturquoise{\partial}x}$
-   * - onlylight
-     - `\onlylight{\LaTeX}`
-     - $\onlylight{\LaTeX}$
-   * - lightanddark
-     - `\lightanddark{\sum}_{n=1}^\infty`
-     - $\lightanddark{\sum}_{n=1}^\infty$
 ::::
 
 
-13. For colours with hyphens we use need to use the class-based command `\class{named-colour}{...}. Replicate the code below:
+13. For colours with hyphens we use need to use the class-based command `\class{named-colour}{...}. Try this using the format shown below:
 
 ```md
 $$ \class{hyphen-color}{\sum}_{n=1}^\infty a_n $$
 ```
+
 14. Test your understanding by creating a block equation where each term is a different colour!
 
 ```{tip}
-This is especially helpful for highlighting changes between equations or focusing attention on specific terms — great for teaching, too!
+This is especially helpful for highlighting changes between equations or focusing attention on specific terms!
 ```
 
 15. When you are ready, commit your changes to the repository by clicking on the green `Commit changes` button.