diff --git a/docs/Makefile b/docs/Makefile
index 62bea9d..fa63ab6 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -1,79 +1,80 @@
 SPHINXOPTS ?=
+SPHINXOPTCOLOR ?= --color
 SPHINXBUILD = sphinx-build
 SOURCEDIR = .
 BUILDDIR = _build
 HTMLDIR = $(BUILDDIR)/html
 SWHPKGDIR ?= sources/swh/
 
 INSTALL_HOST = pergamon.internal.softwareheritage.org
 INSTALL_DIR = /srv/softwareheritage/docs/webroot/devel
 INSTALL_GROUP = swhdev
 INSTALL_PERMS = g+rwX
 
 SPHINXAPIDOC = sphinx-apidoc
 APIDOC_DIR = apidoc
 APIDOC_OPTS = --ext-viewcode --separate
 APIDOC_EXCLUDES = */tests */tests/* */*/tests/* */*/*/tests/*
 APIDOC_EXCLUDES += */migrations */migrations/* */*/migrations/* */*/*/migrations/*
 APIDOC_EXCLUDES += */wsgi.py */*/wsgi.py */*/*/wsgi.py */*/*/wsgi.py
 APIDOC_EXCLUDES += deposit/settings/* web/settings/* dataset/*
 APIDOC_SWH_EXCLUDES = $(patsubst %,$(SWHPKGDIR)/%,$(APIDOC_EXCLUDES))
 
 html: sphinx/html
 
 sphinx/html: links-stamp apidoc-stamp images-stamp rec-build-stamp
 
 links-stamp:
 	bin/ln-sphinx-subprojects
 	touch $@
 
 apidoc: apidoc-stamp
 apidoc-stamp: links-stamp
 	$(SPHINXAPIDOC) \
 		--implicit-namespaces \
 		--templatedir=../swh/docs/templates/ \
 		--maxdepth=3 \
 		$(APIDOC_OPTS) \
 		-o $(APIDOC_DIR) \
 		$(SWHPKGDIR) \
 		$(APIDOC_SWH_EXCLUDES)
 	touch $@
 
 images-stamp:
 	$(MAKE) -C images
 	$(MAKE) -C swh-deposit/images
 	touch $@
 
 # Build documentation recursively in all packages, to make sure that auxiliary,
 # non-sphinx managed documentation artifacts (e.g., schema diagrams) are also
 # built.
 rec-build-stamp: $(wildcard ../../swh-*/docs/*.rst)
 	$(MAKE) -C ../../ docs-assets
 	touch $@
 
 clean: sphinx/clean
 	bin/ln-sphinx-subprojects --remove
 	$(MAKE) -C images clean
 	rm -f *-stamp
 	rm -f $(APIDOC_DIR)/*
 
 distclean: clean
 	make -C ../../ docs-clean
 
 help: sphinx/help
 
 sphinx/clean:
-	$(SPHINXBUILD) -M clean "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS)
+	$(SPHINXBUILD) -M clean "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(SPHINXOPTCOLOR)
 
 sphinx/%:
-	$(SPHINXBUILD) -b $* "$(SOURCEDIR)" "$(BUILDDIR)/$*" $(SPHINXOPTS)
+	$(SPHINXBUILD) -b $* "$(SOURCEDIR)" "$(BUILDDIR)/$*" $(SPHINXOPTS) $(SPHINXOPTCOLOR)
 
 install: html
 	test -d $(HTMLDIR)
 	rsync -rlvuz --delete $(BUILDDIR)/html/ $(INSTALL_HOST):$(INSTALL_DIR)/
 	ssh $(INSTALL_HOST) \
 		"find $(INSTALL_DIR) -not -group $(INSTALL_GROUP) -exec chgrp -v $(INSTALL_GROUP) {} + ; \
 		 find $(INSTALL_DIR) -not -perm -ug=rw,o=r -exec chmod -v ug+rw,o+r {} + ; \
 		 find $(INSTALL_DIR) -type d -not -perm -g=xs,ou=x -exec chmod -v g+xs,ou+x {} +"
 
 .PHONY: help html clean distclean install images-stamp
diff --git a/tox.ini b/tox.ini
index 3d92169..104505f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,41 +1,41 @@
 [tox]
 envlist=flake8,black
 
 [testenv]
 basepython = python3
-passenv = SPHINXOPTS JAVA_HOME
+passenv = SPHINXOPTS SPHINXOPTCOLOR JAVA_HOME
 
 [testenv:sphinx]
 extras =
   building
 deps =
   django < 3
   pifpaf
 setenv =
   SWHPKGDIR = {envsitepackagesdir}/swh
 commands =
   {envpython} -m pifpaf run postgresql -- make -C docs {posargs:html}
 
 [testenv:sphinx-dev]
 whitelist_externals = make
 # workaround really long dependencies installation due to the
 # new pip resolver and its backtracking processes
 install_command = make pip-install-swh-dev {packages}
 setenv =
   SWHPKGDIR = {envsitepackagesdir}/swh
 commands =
   {envpython} -m pifpaf run postgresql -- make -C docs {posargs:html}
 
 [testenv:black]
 skip_install = true
 deps =
   black==19.10b0
 commands =
   {envpython} -m black --check swh
 
 [testenv:flake8]
 skip_install = true
 deps =
   flake8
 commands =
   {envpython} -m flake8