Custom theme with quantmod library

On Wed, 14 Jan 2026, Andre Luiz Tietbohl Ramos writes:

Hello,

Is there a way to customize quantmod theme colors?  This great library
works fine however I rather change its color theme.  So far, I have been
able to use both white and black themes.
I tried to use the chartSeries theme command described below to no avail.
I tried even without a theme name, e.g. white or black. An example is below,

stock.plot <- chartSeries(stock.time_interval,  ## ativo,
                          name = stock.name,
                          type = "candlestick",
                          subset='2025-07::2026-01',
                          theme = chartTheme("white", up.col='darkgreen',
dn.col='darkred',
                                             bg.col='gray',
selection.color='gray'),
                          TA = NULL
                          )

Could anyone help, please?

TIA,

--
Andre Luiz Tietbohl Ramos, PhD

With quantmod 0.4.28 and R 4.5.2, and ESS (but on GNU/Linux),
I can change colours, e. g.

    library("quantmod")
    getSymbols("AAPL")
    
    chartSeries(
        AAPL,
        type = "candlestick",
        subset = '2025-07::2026-01',
        theme = chartTheme("black",
                           up.col = "blue"))

gives me "blue" up-bars.  The same example also works
when I run it from a terminal.

Could this be some Apple-specific thing?