diff --git a/gt_extras/colors.py b/gt_extras/colors.py
index ffab65a..3f9c840 100644
--- a/gt_extras/colors.py
+++ b/gt_extras/colors.py
@@ -109,8 +109,8 @@ def gt_highlight_cols(
 def gt_hulk_col_numeric(
     gt: GT,
     columns: SelectExpr = None,
-    palette: str | list[str] | None = "PRGn",
-    domain: list[str] | list[int] | list[float] | None = None,
+    palette: str | list[str] = "PRGn",
+    domain: list[int] | list[float] | None = None,
     na_color: str | None = None,
     alpha: int | float | None = None,  # TODO: see note
     reverse: bool = False,
diff --git a/gt_extras/html.py b/gt_extras/html.py
index 91b3de5..8c198dc 100644
--- a/gt_extras/html.py
+++ b/gt_extras/html.py
@@ -38,8 +38,8 @@ def gt_hyperlink(text: str, url: str, new_tab: bool = True) -> int:
 def with_tooltip(
     label: str,
     tooltip: str,
-    text_decoration_style: Literal["solid", "dotted"] | None = "dotted",
-    color: str | None = "blue",
+    text_decoration_style: Literal["solid", "dotted", "none"] = "dotted",
+    color: str | Literal["none"] = "blue",
 ) -> str:
     """
     Create HTML text with tooltip functionality for use in GT table cells.
@@ -58,11 +58,10 @@ def with_tooltip(
 
     text_decoration_style
         A string indicating the style of underline decoration. Options are `"solid"`,
-        `"dotted"`, or `None`. If nothing is provided, then `"dotted"` will be used as a default.
+        `"dotted"`, or "none".
 
     color
-        A string indicating the text color. If `None`, no color styling is applied.
-        If nothing is provided, then `"blue"` will be used as a default.
+        A string indicating the text color. If "none", no color styling is applied.
 
     Returns
     -------
@@ -71,18 +70,21 @@ def with_tooltip(
     """
 
     # Throw if `text_decoration_style` is not one of the allowed values
-    if text_decoration_style not in [None, "solid", "dotted"]:
-        raise ValueError("Text_decoration_style must be one of `None`, 'solid', or 'dotted'")
+    if text_decoration_style not in ["none", "solid", "dotted"]:
+        raise ValueError("Text_decoration_style must be one of 'none', 'solid', or 'dotted'")
+    
+    if color is None:
+        raise ValueError("color must be a string or 'none', not None.")
 
     style = "cursor: help; "
 
-    if text_decoration_style is not None:
+    if text_decoration_style != "none":
         style += "text-decoration: underline; "
         style += f"text-decoration-style: {text_decoration_style}; "
     else:
         style += "text-decoration: none; "
 
-    if color is not None:
+    if color != "none":
         style += f"color: {color}; "
 
     return f'<abbr style="{style}" title="{tooltip}">{label}</abbr>'
diff --git a/gt_extras/icons.py b/gt_extras/icons.py
index 0023b5b..7e4b30f 100644
--- a/gt_extras/icons.py
+++ b/gt_extras/icons.py
@@ -14,18 +14,18 @@
 def fa_icon_repeat(
     name: str = "star",
     repeats: int = 1,
-    fill: str | None = "black",
-    fill_opacity: int | str | None = 1,
+    fill: str = "black",
+    fill_opacity: int | str = 1,
     stroke: str | None = None,
     stroke_width: str | None = None,
     stroke_opacity: int | str | None = None,
     height: str | None = None,
     width: str | None = None,
-    margin_left: str | None = "auto",
-    margin_right: str | None = "0.2em",
-    position: str | None = "relative",
+    margin_left: str = "auto",
+    margin_right: str = "0.2em",
+    position: str = "relative",
     title: str | None = None,
-    a11y: Literal["deco", "sem"] | None = "deco",
+    a11y: Literal["deco", "sem", "none"] = "deco",
 ) -> str:
     """
     Create repeated FontAwesome SVG icons as HTML.
@@ -75,7 +75,8 @@ def fa_icon_repeat(
         The title (tooltip) for the icon.
 
     a11y
-        Accessibility mode: `"deco"` for decorative, `"sem"` for semantic.
+        Accessibility mode: `"deco"` for decorative, `"sem"` for semantic, `"none"` will result in
+        no accessibility features.
 
     Returns
     -------
diff --git a/gt_extras/plotting.py b/gt_extras/plotting.py
index f2b6f07..4b5e80e 100644
--- a/gt_extras/plotting.py
+++ b/gt_extras/plotting.py
@@ -34,7 +34,7 @@
 
 def gt_plt_bar(
     gt: GT,
-    columns: SelectExpr | None = None,
+    columns: SelectExpr = None,
     fill: str = "purple",
     bar_height: int = 20,
     height: int = 30,
diff --git a/gt_extras/tests/test_html.py b/gt_extras/tests/test_html.py
index 1507ca7..ed6faaa 100644
--- a/gt_extras/tests/test_html.py
+++ b/gt_extras/tests/test_html.py
@@ -67,18 +67,29 @@ def test_with_tooltip_underline_fail():
         with_tooltip("1", "Number One", text_decoration_style="underline")
 
 
-def test_with_tooltip_no_decoration():
-    result = with_tooltip("1", "Number One", text_decoration_style=None)
+def test_with_tooltip_None_color_fail():
+    with pytest.raises(ValueError):
+        with_tooltip("1", "Number One", color=None)
+
+
+def test_with_tooltip_underline_style_none():
+    result = with_tooltip("1", "Number One", text_decoration_style="none")
     expected = '<abbr style="cursor: help; text-decoration: none; color: blue; " title="Number One">1</abbr>'
     assert result == expected
 
 
-def test_with_tooltip_no_color():
-    result = with_tooltip("1", "Number One", color=None)
+def test_with_tooltip_color_none_pass():
+    result = with_tooltip("1", "Number One", color="none")
     expected = '<abbr style="cursor: help; text-decoration: underline; text-decoration-style: dotted; " title="Number One">1</abbr>'
     assert result == expected
 
 
+def test_with_tooltip_custom_color():
+    result = with_tooltip("1", "Number One", color="red")
+    expected = '<abbr style="cursor: help; text-decoration: underline; text-decoration-style: dotted; color: red; " title="Number One">1</abbr>'
+    assert result == expected
+
+
 def test_with_tooltip_in_table():
     df = pd.DataFrame(
         {
diff --git a/gt_extras/tests/test_themes.py b/gt_extras/tests/test_themes.py
index 6a1d05b..3d78fac 100644
--- a/gt_extras/tests/test_themes.py
+++ b/gt_extras/tests/test_themes.py
@@ -73,7 +73,6 @@ def test_theme_pff_fonts_snap(snapshot, mini_gt):
 def test_theme_pff_dividers(mini_gt):
     themed_gt = gt_theme_pff(gt=mini_gt, divider="num")
     html = themed_gt.as_raw_html()
-    print(html)
     assert "border-left: 2px solid lightgrey" in html