diff --git a/.github/workflows/ci-tests.yml b/.github/workflows/ci-tests.yml
index 5f1b2397ef..1be20ee642 100644
--- a/.github/workflows/ci-tests.yml
+++ b/.github/workflows/ci-tests.yml
@@ -136,6 +136,8 @@ jobs:
       - name: "iris ${{ matrix.session }}"
         env:
           PY_VER: ${{ matrix.python-version }}
+          # Force coloured output on GitHub Actions.
+          PY_COLORS: "1"
         run: |
           nox --session ${{ matrix.session }} -- --verbose ${{ matrix.coverage }}
 
diff --git a/docs/src/whatsnew/latest.rst b/docs/src/whatsnew/latest.rst
index bf8a75136d..295d809ac4 100644
--- a/docs/src/whatsnew/latest.rst
+++ b/docs/src/whatsnew/latest.rst
@@ -98,10 +98,13 @@ This document explains the changes made to Iris for this release
    have been updated to comply and some rules have been ignored for now.
    (:pull:`5762`)
 
+#. `@jfrost-mo`_ enabled colour output for pytest on GitHub Actions. (:pull:`5895`)
+
 .. comment
     Whatsnew author names (@github name) in alphabetical order. Note that,
     core dev names are automatically included by the common_links.inc:
 
+.. _@jfrost-mo: https://github.com/jfrost-mo
 
 
 
@@ -111,4 +114,4 @@ This document explains the changes made to Iris for this release
 .. _Pull Request Labeler GitHub action: https://github.com/actions/labeler
 .. _NPY002: https://docs.astral.sh/ruff/rules/numpy-legacy-random/
 .. _numpydoc validation: https://numpydoc.readthedocs.io/en/latest/validation.html#
-.. _Dask version 2024.2.1: https://docs.dask.org/en/stable/changelog.html#v2024-2-1
\ No newline at end of file
+.. _Dask version 2024.2.1: https://docs.dask.org/en/stable/changelog.html#v2024-2-1