diff --git a/lib/elixir/lib/inspect.ex b/lib/elixir/lib/inspect.ex
index 7b30699f8d..99e8a29118 100644
--- a/lib/elixir/lib/inspect.ex
+++ b/lib/elixir/lib/inspect.ex
@@ -541,8 +541,7 @@ defimpl Inspect, for: Any do
       _ -> Inspect.Map.inspect(map, opts)
     else
       dunder ->
-        is_struct = :maps.keys(dunder) == :maps.keys(map)
-        if is_struct do
+        if :maps.keys(dunder) == :maps.keys(map) do
           pruned = :maps.remove(:__exception__, :maps.remove(:__struct__, map))
           colorless_opts = %{opts | syntax_colors: []}
           Inspect.Map.inspect(pruned, Inspect.Atom.inspect(struct, colorless_opts), opts)
diff --git a/lib/elixir/lib/inspect/algebra.ex b/lib/elixir/lib/inspect/algebra.ex
index facf0df2a7..0646774a7f 100644
--- a/lib/elixir/lib/inspect/algebra.ex
+++ b/lib/elixir/lib/inspect/algebra.ex
@@ -61,6 +61,8 @@ defmodule Inspect.Opts do
             safe: true,
             syntax_colors: []
 
+  @type color_key :: atom
+
   # TODO: Deprecate char_lists key and :as_char_lists value by v1.5
   @type t :: %__MODULE__{
                structs: boolean,
@@ -72,8 +74,8 @@ defmodule Inspect.Opts do
                base: :decimal | :binary | :hex | :octal,
                pretty: boolean,
                safe: boolean,
-               syntax_colors: [{atom, IO.ANSI.ansidata}]
-  }
+               syntax_colors: [{color_key, IO.ANSI.ansidata}]
+             }
 end
 
 defmodule Inspect.Error do
@@ -163,8 +165,6 @@ defmodule Inspect.Algebra do
 
   @type t :: :doc_nil | :doc_line | doc_cons | doc_nest | doc_break | doc_group | doc_color | binary
 
-  @type color_identifier :: atom
-
   @typep doc_cons :: {:doc_cons, t, t}
   defmacrop doc_cons(left, right) do
     quote do: {:doc_cons, unquote(left), unquote(right)}
@@ -308,22 +308,18 @@ defmodule Inspect.Algebra do
   end
 
   @doc """
-  Colors a document if a the identifier has a color in the options.
+  Colors a document if the `color_key` has a color in the options.
   """
-  @spec color(t, color_identifier, Inspect.Opts.t) :: doc_color
-  def color(doc, identifier, %Inspect.Opts{syntax_colors: syntax_colors}) when is_doc(doc) do
-    precolor = Keyword.get(syntax_colors, identifier)
-    if precolor do
+  @spec color(t, Inspect.Opts.color_key, Inspect.Opts.t) :: doc_color
+  def color(doc, color_key, %Inspect.Opts{syntax_colors: syntax_colors}) when is_doc(doc) do
+    if precolor = Keyword.get(syntax_colors, color_key) do
       postcolor = Keyword.get(syntax_colors, :reset, :reset)
-      concat(
-        doc_color(doc, List.wrap(precolor)),
-        doc_color(empty(), List.wrap(postcolor)))
+      concat(doc_color(doc, precolor), doc_color(empty(), postcolor))
     else
       doc
     end
   end
 
-
   @doc ~S"""
   Nests the given document at the given `level`.
 
diff --git a/lib/elixir/test/elixir/inspect/algebra_test.exs b/lib/elixir/test/elixir/inspect/algebra_test.exs
index b477ed3e1d..e5ca781785 100644
--- a/lib/elixir/test/elixir/inspect/algebra_test.exs
+++ b/lib/elixir/test/elixir/inspect/algebra_test.exs
@@ -29,7 +29,7 @@ defmodule Inspect.AlgebraTest do
     # Consistent with definitions
     assert empty() == :doc_nil
 
-    # Consistent of corresponding sdoc
+    # Consistent with corresponding sdoc
     assert sdoc(empty()) == []
 
     # Consistent formatting
@@ -102,19 +102,17 @@ defmodule Inspect.AlgebraTest do
     assert color(empty(), :atom, opts) == empty()
 
     opts = %Inspect.Opts{syntax_colors: [atom: :red]}
-    assert color("Hi", :atom, opts) == concat(
-      {:doc_color, "Hi", [:red]},
-      {:doc_color, empty(), [:reset]}
-    )
+    doc1 = {:doc_color, "Hi", :red}
+    doc2 = {:doc_color, empty(), :reset}
+    assert color("Hi", :atom, opts) == concat(doc1, doc2)
 
     opts = %Inspect.Opts{syntax_colors: [reset: :red]}
     assert color(empty(), :atom, opts) == empty()
 
     opts = %Inspect.Opts{syntax_colors: [number: :cyan, reset: :red]}
-    assert color("123", :number, opts) == concat(
-      {:doc_color, "123", [:cyan]},
-      {:doc_color, empty(), [:red]}
-    )
+    doc1 = {:doc_color, "123", :cyan}
+    doc2 = {:doc_color, empty(), :red}
+    assert color("123", :number, opts) == concat(doc1, doc2)
 
     # Consistent formatting
     opts = %Inspect.Opts{syntax_colors: [atom: :cyan]}
diff --git a/lib/elixir/test/elixir/inspect_test.exs b/lib/elixir/test/elixir/inspect_test.exs
index fbd53cd56a..c4b4c05859 100644
--- a/lib/elixir/test/elixir/inspect_test.exs
+++ b/lib/elixir/test/elixir/inspect_test.exs
@@ -203,21 +203,21 @@ defmodule Inspect.TupleTest do
 
     opts = [syntax_colors: [reset: :cyan]]
     assert inspect({}, opts) == "{}"
-    assert inspect({:X, :Y}, opts) == "{:X, :Y}"
+    assert inspect({:x, :y}, opts) == "{:x, :y}"
 
     opts = [syntax_colors: [reset: :cyan, atom: :red]]
     assert inspect({}, opts) == "{}"
-    assert inspect({:X, :Y}, opts) ==
-      "{\e[31m:X\e[36m, \e[31m:Y\e[36m}"
+    assert inspect({:x, :y}, opts) ==
+      "{\e[31m:x\e[36m, \e[31m:y\e[36m}"
 
     opts = [syntax_colors: [tuple: :green, reset: :cyan, atom: :red]]
     assert inspect({}, opts) == "\e[32m{\e[36m\e[32m}\e[36m"
-    assert inspect({:X, :Y}, opts) ==
-      "\e[32m{\e[36m" <>
-      "\e[31m:X\e[36m" <>
-      "\e[32m,\e[36m " <>
-      "\e[31m:Y\e[36m" <>
-      "\e[32m}\e[36m"
+    assert inspect({:x, :y}, opts) ==
+           "\e[32m{\e[36m" <>
+           "\e[31m:x\e[36m" <>
+           "\e[32m,\e[36m " <>
+           "\e[31m:y\e[36m" <>
+           "\e[32m}\e[36m"
   end
 end
 
@@ -296,51 +296,51 @@ defmodule Inspect.ListTest do
 
     opts = [syntax_colors: [reset: :cyan]]
     assert inspect([], opts) == "[]"
-    assert inspect([:X, :Y], opts) ==
-      "[:X, :Y]"
+    assert inspect([:x, :y], opts) ==
+           "[:x, :y]"
 
     opts = [syntax_colors: [reset: :cyan, atom: :red]]
     assert inspect([], opts) == "[]"
-    assert inspect([:X, :Y], opts) ==
-      "[\e[31m:X\e[36m, \e[31m:Y\e[36m]"
+    assert inspect([:x, :y], opts) ==
+           "[\e[31m:x\e[36m, \e[31m:y\e[36m]"
 
     opts = [syntax_colors: [reset: :cyan, atom: :red, list: :green]]
     assert inspect([], opts) == "\e[32m[]\e[36m"
-    assert inspect([:X, :Y], opts) ==
-      "\e[32m[\e[36m" <>
-      "\e[31m:X\e[36m" <>
-      "\e[32m,\e[36m " <>
-      "\e[31m:Y\e[36m" <>
-      "\e[32m]\e[36m"
+    assert inspect([:x, :y], opts) ==
+           "\e[32m[\e[36m" <>
+           "\e[31m:x\e[36m" <>
+           "\e[32m,\e[36m " <>
+           "\e[31m:y\e[36m" <>
+           "\e[32m]\e[36m"
   end
 
   test "keyword with colors" do
     opts = [syntax_colors: [reset: :cyan, list: :green, number: :blue]]
     assert inspect([], opts) == "\e[32m[]\e[36m"
     assert inspect([a: 9999], opts) ==
-      "\e[32m[\e[36m" <>
-      "a: " <>
-      "\e[34m9999\e[36m" <>
-      "\e[32m]\e[36m"
+           "\e[32m[\e[36m" <>
+           "a: " <>
+           "\e[34m9999\e[36m" <>
+           "\e[32m]\e[36m"
 
     opts = [syntax_colors: [reset: :cyan, atom: :red, list: :green, number: :blue]]
     assert inspect([], opts) == "\e[32m[]\e[36m"
     assert inspect([a: 9999], opts) ==
-      "\e[32m[\e[36m" <>
-      "\e[31ma: \e[36m" <>
-      "\e[34m9999\e[36m" <>
-      "\e[32m]\e[36m"
+           "\e[32m[\e[36m" <>
+           "\e[31ma: \e[36m" <>
+           "\e[34m9999\e[36m" <>
+           "\e[32m]\e[36m"
   end
 
   test "limit with colors" do
     opts = [limit: 1, syntax_colors: [reset: :cyan, list: :green, atom: :red]]
     assert inspect([], opts) == "\e[32m[]\e[36m"
-    assert inspect([:X, :Y], opts) ==
-      "\e[32m[\e[36m" <>
-      "\e[31m:X\e[36m" <>
-      "\e[32m,\e[36m " <>
-      "..." <>
-      "\e[32m]\e[36m"
+    assert inspect([:x, :y], opts) ==
+           "\e[32m[\e[36m" <>
+           "\e[31m:x\e[36m" <>
+           "\e[32m,\e[36m " <>
+           "..." <>
+           "\e[32m]\e[36m"
   end
 end
 
@@ -422,20 +422,20 @@ defmodule Inspect.MapTest do
   test "colors" do
     opts = [syntax_colors: [reset: :cyan, atom: :red, number: :magenta]]
     assert inspect(%{1 => 2}, opts) ==
-      "%{\e[35m1\e[36m => \e[35m2\e[36m}"
+           "%{\e[35m1\e[36m => \e[35m2\e[36m}"
 
     assert inspect(%{a: 1}, opts) ==
-      "%{\e[31ma: \e[36m\e[35m1\e[36m}"
+           "%{\e[31ma: \e[36m\e[35m1\e[36m}"
 
     assert inspect(%Public{key: 1}, opts) ==
-      "%Inspect.MapTest.Public{\e[31mkey: \e[36m\e[35m1\e[36m}"
+           "%Inspect.MapTest.Public{\e[31mkey: \e[36m\e[35m1\e[36m}"
 
     opts = [syntax_colors: [reset: :cyan, atom: :red, map: :green, number: :blue]]
     assert inspect(%{a: 9999}, opts) ==
-      "\e[32m%{\e[36m" <>
-      "\e[31ma: \e[36m" <>
-      "\e[34m9999\e[36m" <>
-      "\e[32m}\e[36m"
+           "\e[32m%{\e[36m" <>
+           "\e[31ma: \e[36m" <>
+           "\e[34m9999\e[36m" <>
+           "\e[32m}\e[36m"
   end
 end
 
@@ -485,8 +485,8 @@ defmodule Inspect.OthersTest do
     opts = [syntax_colors: []]
     assert "#Function<" <> _ = inspect(fun(), opts)
     opts = [syntax_colors: [reset: :red]]
-    assert "#Function<" <> _ = inspect(fun(), opts)
-    assert String.ends_with?(inspect(fun(), opts), ">")
+    assert "#Function<" <> rest = inspect(fun(), opts)
+    assert String.ends_with?(rest, ">")
   end
 
   test "map set" do
@@ -498,8 +498,8 @@ defmodule Inspect.OthersTest do
     opts = [syntax_colors: []]
     assert "#PID<" <> _ = inspect(self(), opts)
     opts = [syntax_colors: [reset: :cyan]]
-    assert "#PID" <> _ = inspect(self(), opts)
-    assert String.ends_with?(inspect(self(), opts), ">")
+    assert "#PID<" <> rest = inspect(self(), opts)
+    assert String.ends_with?(rest, ">")
   end
 
   test "references" do
@@ -509,11 +509,11 @@ defmodule Inspect.OthersTest do
   test "regex" do
     assert inspect(~r(foo)m) == "~r/foo/m"
     assert inspect(Regex.compile!("\a\b\d\e\f\n\r\s\t\v/")) ==
-      "~r/\\a\\x08\\x7F\\x1B\\f\\n\\r \\t\\v\\//"
+           "~r/\\a\\x08\\x7F\\x1B\\f\\n\\r \\t\\v\\//"
     assert inspect(~r<\a\b\d\e\f\n\r\s\t\v/>) ==
-      "~r/\\a\\b\\d\\e\\f\\n\\r\\s\\t\\v\\//"
+           "~r/\\a\\b\\d\\e\\f\\n\\r\\s\\t\\v\\//"
     opts = [syntax_colors: [regex: :red]]
     assert inspect(~r/hi/, opts) ==
-      "\e[31m~r/hi/\e[0m"
+           "\e[31m~r/hi/\e[0m"
   end
 end
diff --git a/lib/iex/lib/iex/config.ex b/lib/iex/lib/iex/config.ex
index fe5a494759..19214e2a5f 100644
--- a/lib/iex/lib/iex/config.ex
+++ b/lib/iex/lib/iex/config.ex
@@ -175,7 +175,7 @@ defmodule IEx.Config do
   defp merge_option(:default_prompt, _old, new) when is_binary(new), do: new
   defp merge_option(:alive_prompt, _old, new) when is_binary(new), do: new
   defp merge_option(:width, _old, new) when is_integer(new), do: new
-  defp merge_option(k, _old, new) do
-    raise ArgumentError, "invalid configuration or value for pair #{inspect k} - #{inspect new}"
+  defp merge_option(key, _old, new) do
+    raise ArgumentError, "invalid configuration or value for pair #{inspect key} - #{inspect new}"
   end
 end