Format colors: Create a palette of the available colors

This example create a sample palette of the the defined colors, some user defined RGB colors, and the theme palette color available in therust_xlsxwriter library.

See also Working with Colors.

Images of the output file:

Code to generate the output file:

// SPDX-License-Identifier: MIT OR Apache-2.0
//
// Copyright 2022-2024, John McNamara, jmcnamara@cpan.org

//! A demonstration of the RGB and Theme colors palettes available in the
//! rust_xlsxwriter library.

use rust_xlsxwriter::*;

fn main() -> Result<(), XlsxError> {
    // Create a new Excel file object.
    let mut workbook = Workbook::new();

    // Add a worksheet for the RGB colors.
    let worksheet = workbook.add_worksheet().set_name("RGB Colors")?;

    // Write some enum defined colors to cells.
    let color_format = Format::new().set_background_color(Color::Black);
    worksheet.write_string(0, 0, "Black")?;
    worksheet.write_blank(0, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Blue);
    worksheet.write_string(1, 0, "Blue")?;
    worksheet.write_blank(1, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Brown);
    worksheet.write_string(2, 0, "Brown")?;
    worksheet.write_blank(2, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Cyan);
    worksheet.write_string(3, 0, "Cyan")?;
    worksheet.write_blank(3, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Gray);
    worksheet.write_string(4, 0, "Gray")?;
    worksheet.write_blank(4, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Green);
    worksheet.write_string(5, 0, "Green")?;
    worksheet.write_blank(5, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Lime);
    worksheet.write_string(6, 0, "Lime")?;
    worksheet.write_blank(6, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Magenta);
    worksheet.write_string(7, 0, "Magenta")?;
    worksheet.write_blank(7, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Navy);
    worksheet.write_string(8, 0, "Navy")?;
    worksheet.write_blank(8, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Orange);
    worksheet.write_string(9, 0, "Orange")?;
    worksheet.write_blank(9, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Pink);
    worksheet.write_string(10, 0, "Pink")?;
    worksheet.write_blank(10, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Purple);
    worksheet.write_string(11, 0, "Purple")?;
    worksheet.write_blank(11, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Red);
    worksheet.write_string(12, 0, "Red")?;
    worksheet.write_blank(12, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Silver);
    worksheet.write_string(13, 0, "Silver")?;
    worksheet.write_blank(13, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::White);
    worksheet.write_string(14, 0, "White")?;
    worksheet.write_blank(14, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::Yellow);
    worksheet.write_string(15, 0, "Yellow")?;
    worksheet.write_blank(15, 1, &color_format)?;

    // Write some user defined RGB colors to cells.
    let color_format = Format::new().set_background_color(Color::RGB(0xFF7F50));
    worksheet.write_string(16, 0, "#FF7F50")?;
    worksheet.write_blank(16, 1, &color_format)?;

    let color_format = Format::new().set_background_color(Color::RGB(0xDCDCDC));
    worksheet.write_string(17, 0, "#DCDCDC")?;
    worksheet.write_blank(17, 1, &color_format)?;

    // Write a RGB color with the shorter Html string variant.
    let color_format = Format::new().set_background_color("#6495ED");
    worksheet.write_string(18, 0, "#6495ED")?;
    worksheet.write_blank(18, 1, &color_format)?;

    // Write a RGB color with the optional u32 variant.
    let color_format = Format::new().set_background_color(0xDAA520);
    worksheet.write_string(19, 0, "#DAA520")?;
    worksheet.write_blank(19, 1, &color_format)?;

    // Add a worksheet for the Theme colors.
    let worksheet = workbook.add_worksheet().set_name("Theme Colors")?;

    // Create a cell with each of the theme colors.
    for row in 0..=5u32 {
        for col in 0..=9u16 {
            let color = col as u8;
            let shade = row as u8;
            let theme_color = Color::Theme(color, shade);
            let text = format!("({}, {})", col, row);

            let mut font_color = Color::White;
            if col == 0 {
                font_color = Color::Default;
            }

            let color_format = Format::new()
                .set_background_color(theme_color)
                .set_font_color(font_color)
                .set_align(FormatAlign::Center);

            worksheet.write_string_with_format(row, col, &text, &color_format)?;
        }
    }

    // Save the file to disk.
    workbook.save("colors.xlsx")?;

    Ok(())
}