The tab_style() function

Use exibble to create a gt table. Add styles that are to be applied to data cells that satisfy a condition (using tab_style()).

exibble |>
  dplyr::select(num, currency) |>
  gt() |>
  fmt_number(
    columns = c(num, currency),
    decimals = 1
  ) |>
  tab_style(
    style = list(
      cell_fill(color = "lightcyan"),
      cell_text(weight = "bold")
      ),
    locations = cells_body(
      columns = num,
      rows = num >= 5000
    )
  ) |>
  tab_style(
    style = list(
      cell_fill(color = "#F9E3D6"),
      cell_text(style = "italic")
      ),
    locations = cells_body(
      columns = currency,
      rows = currency < 100
    )
  )

num	currency
0.1	50.0
2.2	17.9
33.3	1.4
444.4	65,100.0
5,550.0	1,325.8
NA	13.3
777,000.0	NA
8,880,000.0	0.4

Use sp500 to create a gt table. Color entire rows of cells based on values in a particular column.

sp500 |>
  dplyr::filter(
    date >= "2015-12-01" &
    date <= "2015-12-15"
  ) |>
  dplyr::select(-c(adj_close, volume)) |>
  gt() |>
  tab_style(
    style = cell_fill(color = "lightgreen"),
    locations = cells_body(rows = close > open)
  ) |>
  tab_style(
    style = list(
      cell_fill(color = "red"),
      cell_text(color = "white")
      ),
    locations = cells_body(rows = open > close)
  )

date	open	high	low	close
2015-12-15	2025.55	2053.87	2025.55	2043.41
2015-12-14	2013.37	2022.92	1993.26	2021.94
2015-12-11	2047.27	2047.27	2008.80	2012.37
2015-12-10	2047.93	2067.65	2045.67	2052.23
2015-12-09	2061.17	2080.33	2036.53	2047.62
2015-12-08	2073.39	2073.85	2052.32	2063.59
2015-12-07	2090.42	2090.42	2066.78	2077.07
2015-12-04	2051.24	2093.84	2051.24	2091.69
2015-12-03	2080.71	2085.00	2042.35	2049.62
2015-12-02	2101.71	2104.27	2077.11	2079.51
2015-12-01	2082.93	2103.37	2082.93	2102.63

Use exibble to create a gt table. Replace missing values with the sub_missing() function and then add styling to the char column with cell_fill() and with a CSS style declaration.

exibble |>
  dplyr::select(char, fctr) |>
  gt() |>
  sub_missing() |>
  tab_style(
    style = list(
      cell_fill(color = "lightcyan"),
      "font-variant: small-caps;"
    ),
    locations = cells_body(columns = char)
  )

char	fctr
apricot	one
banana	two
coconut	three
durian	four
—	five
fig	six
grapefruit	seven
honeydew	eight