Colours and themes¶

The same region is the same colour everywhere¶

A dashboard where West is blue in one chart and orange in the next makes people work harder than they should. tabsight gives each value one colour and keeps it:

import tabsight as ts

colors = ts.ColorRegistry()
colors.assign(["West", "East", "Central", "South"])
print(colors.mapping())

Output

{'Central': '#4e79a7', 'East': '#f28e2b', 'South': '#e15759', 'West': '#76b7b2'}

The values are sorted before colours are handed out, so you get the same colours however the rows happen to be ordered. If a colour matters to you, such as your company's red for its home region, pin it:

brand = ts.ColorRegistry(pinned={"West": "#e15759"})
brand.assign(["East", "West", "South"])
print(brand.mapping())

Output

{'West': '#e15759', 'East': '#4e79a7', 'South': '#f28e2b'}

A registry saves with to_dict() and comes back with ts.ColorRegistry.from_dict(...), so next month's dashboard uses the same colours.

Palettes¶

The default, classic10, uses the same ten colours as d3's widely used schemeTableau10. okabe_ito is designed to stay distinguishable for people with colour-vision deficiency, and the print theme uses it. muted is a softer set for dense charts. Pick one with ts.ColorRegistry("okabe_ito"), or for everything with ts.set_defaults(palette="okabe_ito").

Colours have to be hex codes such as #4e79a7. Names like red, rgb() and anything else are rejected. That keeps a colour value from smuggling CSS into an HTML file.

Themes¶

There are three built-in themes: light (white tiles on a pale grey page), dark, and print (pure white, black text, the colour-blind-safe palette and square corners). Each one meets the WCAG AA contrast standard for text, and a test makes sure it stays that way.

To match a brand, start from a built-in theme and change what you need:

from tabsight.warnings import InvalidSpecError

brand_theme = ts.custom_theme("light", accent="#0b5394", font='"Inter", Arial, sans-serif')
print(brand_theme.accent, "|", brand_theme.font)

try:
    ts.custom_theme("light", text="#c8c8c8")
except InvalidSpecError as err:
    print(err)

Output

#0b5394 | "Inter", Arial, sans-serif
theme fails WCAG AA contrast: text on tile is 1.67:1; text on page is 1.55:1; text on header is 1.50:1

The second theme was refused because light grey text on white is hard to read. Font names can only contain letters, digits, spaces, commas, quotes and hyphens, and tabsight never downloads fonts: the default is whatever sans-serif your system already has.