R maximum observations for color scheme in a plot

I am working with a relatively large dataset (n>1000). I have come across a problem when applying "ifelse" in order to specify different colors in a plot.

With a small selection of data, the specified colors are displayed. When using the large dataset, the colors appear as red and green, no matter which colors I specified. So far I have encountered this problem with ggplot2, plotly and condformat (with different data).

E.g.

condformat(fullData[1:500,]) %>%
rule_fill_discrete(title, expression = ifelse(start_var == end_var,  "purple", "orange"))

works, but

condformat(fullData[1:1000,]) %>%
rule_fill_discrete(title, expression = ifelse(start_var == end_var, "purple", "orange"))

will display the colors not in orange and purple, but red and green.

I apologize in advance if this is a trivial question, but my google search remained unsuccesful. Thank you in advance!