-plot 'influence_nb_threads.txt' using 1:2 t "sparse 500K" with linespoints lt 1 lw 2 ps 1 pt 1,\
- 'nb_iter_sec_ex15_juqueen.txt' using 1:4 t "full 500K" with linespoints lt 2 lw 2 ps 2 pt 1
+set style line 1 lc rgb '#0060ad' lt 1 lw 2 pt 1 ps 1.5 # --- blue
+set style line 2 lc rgb '#dd181f' lt 1 lw 2 pt 5 ps 1.5 # --- red
+plot 'influence_nb_threads.txt' using 1:2 t "sparse 500K" with linespoints ls 1,\
+ 'influence_nb_threads.txt' using 1:4 t "full 500K" with linespoints ls 2,\
+ 'influence_nb_threads.txt' using 1:6 t "sparse 50K" with linespoints lt 1 lw 2 ps 1 pt 1,\
+ 'influence_nb_threads.txt' using 1:8 t "full 50K" with linespoints lt 1 lw 2 ps 1 pt 3
+