Added feature to set bg_color using -B flag.

src/cli.rs

@@ -293,6 +293,15 @@ OPTIONS:
     r,g,b
 ";
 
+const HELP_BG_COLORS: &str = "Set background color of Rain with color string name or tuple
+OPTIONS:
+    white,
+    red,
+    blue,
+    green,
+    r,g,b
+";
+
 const HELP_CHARS: &str = "Set what kind of characters are printed as rain.
 OPTIONS:
     all            - This shows most of the Character Groups all at once.
@@ -346,6 +355,8 @@ pub struct Cli {
     pub group: Grouping,
     #[arg(short = 'C', long, help = HELP_COLORS, default_value_t = String::from("green"))]
     pub color: String,
+    #[arg(short = 'B', long, help = HELP_BG_COLORS)]
+    pub bg_color: Option<String>,
     #[arg(short = 'H', long, help = HELP_HEAD, default_value_t = String::from("white"))]
     pub head: String,
     #[arg(short, long, help = HELP_DIRECTION, default_value = "south")]
@@ -365,6 +376,10 @@ impl Cli {
     pub fn rain_color(&self) -> (u8, u8, u8) {
         into_color(&self.color)
     }
+
+    pub fn rain_bg_color(&self) -> Option<(u8, u8, u8)> {
+        self.bg_color.as_ref().map(|col| into_color(col.as_str()))
+    }
     pub fn head_color(&self) -> (u8, u8, u8) {
         into_color(&self.head)
     }

src/main.rs

@@ -5,8 +5,8 @@ mod test;
 use clap::Parser;
 use crossterm::{
     cursor, event, execute, queue,
-    style::{Color, Print, SetForegroundColor},
-    terminal,
+    style::{Color, Print, SetBackgroundColor, SetForegroundColor},
+    terminal::{self, Clear, ClearType},
 };
 use ezemoji::CharGroup;
 use rand::Rng;
@@ -477,7 +477,7 @@ impl App {
     fn run(&mut self, settings: cli::Cli) -> std::io::Result<()> {
         let (w, h) = terminal::size()?;
         let mut rain = Rain::<1024>::new(w as usize, h as usize, &settings);
-        self.setup_terminal()?;
+        self.setup_terminal(&settings)?;
 
         let mut is_running = true;
         while is_running {
@@ -506,9 +506,18 @@ impl App {
     }
 
     #[inline(always)]
-    fn setup_terminal(&mut self) -> std::io::Result<()> {
+    fn setup_terminal(&mut self, settings: &cli::Cli) -> std::io::Result<()> {
         terminal::enable_raw_mode()?;
         execute!(self.stdout, terminal::EnterAlternateScreen, cursor::Hide)?;
+
+        if let Some(col) = settings.rain_bg_color() {
+            execute!(
+                self.stdout,
+                SetBackgroundColor(col.into()),
+                Clear(ClearType::All),
+            )?
+        }
+
         Ok(())
     }