Customizing

Tweak an existing theme

Themes are immutable — each with_* helper returns a new theme, so calls chain and the original is never changed:

from loguru import logger
from loguru_themes import apply_theme, get_theme

my_theme = (
    get_theme("dracula")
    .with_name("my-dracula")        # rename (e.g. before registering)
    .with_color("INFO", "#ffffff")  # one level's color
    .with_icon("error", "!!")       # one level's icon
    .with_fg("#e6e6e6")             # message text color
)
apply_theme(logger, my_theme)

Available helpers: with_name, with_fg, with_accent, with_dim, with_format, with_palette, with_color(level, color), with_level(level, **fields), with_icon(level, icon), with_icons(set_or_mapping), and with_uniform_message(color=...).

One color for every message

Drop the red ERROR / CRITICAL highlight and use a single message color:

plain = get_theme("dracula").with_uniform_message("#e6e6e6")
apply_theme(logger, plain)

Restyle a single level

with_level sets any LevelStyle field — badge (color, bold, bg) and message (msg_fg, msg_bg, msg_bold):

theme = get_theme("dracula").with_level(
    "WARNING", color="#ffd166", bold=True, msg_fg="#ffd166"
)

Build a theme from scratch

from loguru_themes import Theme, LevelStyle, register_theme, apply_theme

ocean = Theme(
    name="ocean",
    levels={
        "TRACE":    LevelStyle("#5b7083"),
        "DEBUG":    LevelStyle("#48cae4"),
        "INFO":     LevelStyle("#90e0ef"),
        "SUCCESS":  LevelStyle("#52b788"),
        "WARNING":  LevelStyle("#ffb703"),
        "ERROR":    LevelStyle("#ef476f", msg_fg="#ef476f"),
        "CRITICAL": LevelStyle("#ff5d8f", bold=True,
                               msg_fg="#ffffff", msg_bg="#d00000", msg_bold=True),
    },
    accent="#48cae4",
    dim="#5b7083",
    fg="#caf0f8",
)
register_theme(ocean)
apply_theme(logger, "ocean")

You can also apply a Theme directly without registering it: apply_theme(logger, ocean).

Registering

• register_theme(theme) makes it available by name via apply_theme / get_theme.
• Re-registering the same name needs overwrite=True.
• Built-in names can’t be replaced.