Seaborn multi line plot with only one line colored

Question

I am trying to plot a multi line plot using sns but only keeping the US line in red while the other countries are in grey

This is what I have so far:

df = px.data.gapminder()
sns.lineplot(x = 'year', y = 'pop', data = df, hue = 'country', color = 'grey', dashes = False, legend = False)

But this does not change the lines to grey. I was thinking that after this, I could add in US line by itself in red.....

Answer 1

You can use pandas groupby to plot:

fig,ax=plt.subplots()
for c,d in df.groupby('country'):
    color = 'red' if c=='US' else 'grey'
    d.plot(x='year',y='pop', ax=ax, color=color)

ax.legend().remove()

output:

To keep the original colors for a default palette, but grey out the rest, you can choose to pass color='grey' only when the condition is met:

if c in some_list:
    d.plot(...)
    else:
        d.plot(..., color='grey')

---

Or you can define a specific palette as a dictionary:

palette = {c:'red' if c=='US' else 'grey' for c in df.country.unique()}

sns.lineplot(x='year', y='pop', data=df, hue='country', 
             palette=palette, legend=False)

Output: