diff --git a/src/book/mod.rs b/src/book/mod.rs
index 1ebb658..bcd1543 100644
--- a/src/book/mod.rs
+++ b/src/book/mod.rs
@@ -3,10 +3,7 @@ use std::cmp::max;
 use anyhow::{anyhow, Result};
 use ironcalc::{
     base::{
-        expressions::types::Area,
-        types::{Border, Col, Fill, Font, Row, SheetData, Style, Worksheet},
-        worksheet::WorksheetDimension,
-        Model, UserModel,
+        calc_result::Range, expressions::types::Area, types::{Border, Col, Fill, Font, Row, SheetData, Style, Worksheet}, worksheet::WorksheetDimension, Model, UserModel
     },
     export::save_xlsx_to_writer,
     import::load_from_xlsx,
@@ -150,12 +147,13 @@ impl Book {
     }
 
     pub fn new_sheet(&mut self, sheet_name: Option<&str>) -> Result<()> {
-        todo!("We need to figure out how to find the new sheet index so we can rename it");
-        //let (_, idx) = self.model.new_sheet();
-        //if let Some(name) = sheet_name {
-        //    self.set_sheet_name(idx as usize, name)?;
-        //}
-        //Ok(())
+        self.model.new_sheet().map_err(|e| anyhow!(e))?;
+        let idx = self.model.get_selected_sheet();
+        if let Some(name) = sheet_name {
+            self.set_sheet_name(idx as usize, name)?;
+        }
+        self.model.set_selected_sheet(self.current_sheet).map_err(|e| anyhow!(e))?;
+        Ok(())
     }
 
     /// Get the sheet data for the current worksheet.
@@ -347,11 +345,12 @@ impl Book {
         }
     }
 
-    pub fn set_cell_style(&mut self, style: &Style, sheet: u32, cell: &Address) -> Result<()> {
-        todo!()
-        //self.model.set_cell_style(sheet, cell.row as i32, cell.col as i32, style)
-        //    .map_err(|s| anyhow!("Unable to format cell {}", s))?;
-        //Ok(())
+    pub fn set_cell_style(&mut self, style: &[(&str, &str)], area: &Area) -> Result<()> {
+        for (path, val) in style {
+            self.model.update_range_style(area, path, val)
+                .map_err(|s| anyhow!("Unable to format cell {}", s))?;
+        }
+        Ok(())
     }
 
     pub fn set_col_style(&mut self, style: &Style, sheet: u32, col: usize) -> Result<()> {
@@ -582,6 +581,7 @@ impl Book {
             .map_err(|s| anyhow!("Invalid Worksheet: {}", s))?
             .name)
     }
+
     pub(crate) fn get_sheet_by_idx_mut(&mut self, idx: usize) -> Result<&mut Worksheet> {
         todo!("Is there a clean way to do this with UserModel?")
         //Ok(self
diff --git a/src/ui/mod.rs b/src/ui/mod.rs
index 4ef356b..752ae75 100644
--- a/src/ui/mod.rs
+++ b/src/ui/mod.rs
@@ -5,7 +5,7 @@ use crate::book::{AddressRange, Book};
 
 use anyhow::{anyhow, Result};
 use crossterm::event::{self, Event, KeyCode, KeyEventKind, KeyModifiers};
-use ironcalc::base::Model;
+use ironcalc::base::{expressions::types::Area, Model};
 use ratatui::{
     buffer::Buffer,
     layout::{Constraint, Flex, Layout},
@@ -494,25 +494,26 @@ impl<'ws> Workspace<'ws> {
                 Ok(None)
             }
             Ok(Some(Cmd::ColorCell(color))) => {
-                if let Some((start, end)) = self.state.range_select.get_range() {
-                    for ri in start.row..=end.row {
-                        for ci in start.col..=end.col {
-                            let address = Address { row: ri, col: ci };
-                            let sheet = self.book.current_sheet;
-                            let mut style = self.book.get_cell_style(sheet, &address)
-                                .expect("I think this should be impossible.").clone();
-                            style.fill.bg_color = Some(color.to_string());
-                            self.book.set_cell_style(&style, sheet, &address)?;
-                        }
+                let sheet = self.book.current_sheet;
+                let area = if let Some((start, end)) = self.state.range_select.get_range() {
+                    Area {
+                        sheet,
+                        row: start.row as i32,
+                        column: start.col as i32,
+                        width: (end.col - start.col) as i32,
+                        height: (end.row - start.row) as i32
                     }
                 } else {
                     let address = self.book.location.clone();
-                    let sheet = self.book.current_sheet;
-                    let mut style = self.book.get_cell_style(sheet, &address)
-                        .expect("I think this should be impossible.").clone();
-                    style.fill.bg_color = Some(color.to_string());
-                    self.book.set_cell_style(&style, sheet, &address)?;
-                }
+                    Area {
+                        sheet,
+                        row: address.row as i32,
+                        column: address.col as i32,
+                        width: 1,
+                        height: 1
+                    }
+                };
+                self.book.set_cell_style(&[("fill.bg_color", color)], &area)?;
                 Ok(None)
             }
             Ok(None) => {