diff --git a/src/filetypes.rs b/src/filetypes.rs
index b900ece..c4e65fc 100644
--- a/src/filetypes.rs
+++ b/src/filetypes.rs
@@ -46,7 +46,7 @@ impl FileTypes {
                         let code = Self::get_code(filetype);
                         let result = mapping.insert(code, category.clone());
 
-                        if !result.is_none() {
+                        if result.is_some() {
                             return Err(VividError::DuplicateFileType(filetype.to_string()));
                         }
                     } else {
diff --git a/src/main.rs b/src/main.rs
index 9ae0c2e..68429a4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -92,7 +92,7 @@ fn run() -> Result<()> {
         let theme_name_env = env::var("VIVID_THEME").ok();
         let theme_name = sub_matches
             .value_of("theme")
-            .or(theme_name_env.as_ref().map(String::as_str))
+            .or_else(|| theme_name_env.as_ref().map(String::as_str))
             .unwrap_or("molokai");
         let theme_file = format!("{}.yml", theme_name);
 
@@ -105,7 +105,7 @@ fn run() -> Result<()> {
         theme_path_system.push(theme_file);
 
         let theme_path = util::get_first_existing_path(&[&theme_path_user, &theme_path_system])
-            .ok_or(VividError::CouldNotFindTheme(theme_name.to_string()))?;
+            .ok_or_else(|| VividError::CouldNotFindTheme(theme_name.to_string()))?;
         let theme = Theme::from_file(theme_path, color_mode)?;
 
         let mut filetypes_list = filetypes.mapping.keys().collect::<Vec<_>>();
diff --git a/src/theme.rs b/src/theme.rs
index 9c47cde..f504933 100644
--- a/src/theme.rs
+++ b/src/theme.rs
@@ -68,9 +68,9 @@ impl Theme {
     fn get_color(&self, color_str: &str) -> Result<Color> {
         self.colors
             .get(color_str)
-            .map(|c| c.clone())
-            .or(Color::from_hex_str(color_str).ok())
-            .ok_or(VividError::UnknownColor(color_str.to_string()))
+            .cloned()
+            .or_else(|| Color::from_hex_str(color_str).ok())
+            .ok_or_else(|| VividError::UnknownColor(color_str.to_string()))
     }
 
     pub fn get_style(&self, category: CategoryRef) -> Result<String> {