how to change color for one point in the scatter plot

I wanted to separatly color the markers in scatter plot.

e.g i ahve a date:

a=[1:10]'; b=[11:20]';

scatter(a,b,'o','filled');

here i wanted to change the color only for data in the row five (the circled one).

I appreaciate for you help

Answer 1

[Alan Stevens]

a=[1:10]'; b=[11:20]';
scatter(a,b,'o','filled');
hold on
plot(a(5),b(5),'ro','MarkerFaceColor','r')

Answer 2

[KSSV]

a=[1:10]'; b=[11:20]';
scatter(a,b,'o','filled');
hold on
scatter(a(4),b(4),'or','filled')

Also you can use plot

a=[1:10]'; b=[11:20]';
plot(a,b,'.','MarkerSize',20);
hold on
plot(a(4),b(4),'.r','MarkerSize',20);