diff --git a/pyinstrument/__main__.py b/pyinstrument/__main__.py
index ae74047e..568093a9 100644
--- a/pyinstrument/__main__.py
+++ b/pyinstrument/__main__.py
@@ -421,8 +421,11 @@ def compute_render_options(
     """
 
     unicode_support: bool = file_supports_unicode(output_file)
+    color_support: bool = file_supports_color(output_file)
 
-    error, render_options = _compute_render_options(options, renderer_class, unicode_support)
+    error, render_options = _compute_render_options(
+        options, renderer_class, unicode_support, color_support
+    )
     if error is not None:
         raise OptionsParseError(error)
     assert render_options is not None
@@ -430,13 +433,16 @@ def compute_render_options(
 
 
 def _compute_render_options(
-    options: CommandLineOptions, renderer_class: type[renderers.Renderer], unicode_support: bool
+    options: CommandLineOptions,
+    renderer_class: type[renderers.Renderer],
+    unicode_support: bool,
+    color_support: bool,
 ) -> Tuple[Optional[str], Optional[dict[str, Any]]]:
     """
     Similar as compute_render_options, but return a tuple (error message, data)
     if there is an error; this will let us reuse _compute_render_options in magics.
 
-    output_file, has been replaced by unicode_support:bool
+    output_file, has been replaced by unicode_support:bool, color_support:bool
     """
     # parse show/hide options
     if options.hide_fnmatch is not None and options.hide_regex is not None:
@@ -476,7 +482,7 @@ def _compute_render_options(
         unicode_override = options.unicode is not None
         color_override = options.color is not None
         unicode: Any = options.unicode if unicode_override else unicode_support
-        color: Any = options.color if color_override else unicode_support
+        color: Any = options.color if color_override else color_support
 
         render_options.update({"unicode": unicode, "color": color})
 
diff --git a/pyinstrument/magic/magic.py b/pyinstrument/magic/magic.py
index e5ed5880..25fabe8f 100644
--- a/pyinstrument/magic/magic.py
+++ b/pyinstrument/magic/magic.py
@@ -242,7 +242,7 @@ def pyinstrument(self, line, cell=None):
             return
 
         html_error, html_config = _compute_render_options(
-            args, renderer_class=HTMLRenderer, unicode_support=True
+            args, renderer_class=HTMLRenderer, unicode_support=True, color_support=True
         )
         if html_error is not None:
             raise ValueError(html_error)
diff --git a/test/test_cmdline.py b/test/test_cmdline.py
index c787c1ae..d3f7f02d 100644
--- a/test/test_cmdline.py
+++ b/test/test_cmdline.py
@@ -269,7 +269,7 @@ def test_invocation_machinery_is_trimmed(self, pyinstrument_invocation, tmp_path
         print(output)
 
         first_profiling_line = re.search(r"^\d+(\.\d+)?\s+([^\s]+)\s+(.*)", output, re.MULTILINE)
-        assert first_profiling_line
+        assert first_profiling_line, output
 
         function_name = first_profiling_line.group(2)
         location = first_profiling_line.group(3)