how to - index dependency in phase space plot

i have a vector X and a vector Y containing 10001 values each .

i want to plot them against eachother with some indicator of the index of each point .

for example , lets say the vectors are 5 valued long as follows :

X=[3,1,6,12,89] Y=[1,4,8,5,22]

i look at the plot and i see five points

A=(3,1) . B=(1,4) . C=(6,8).D=(12,5) E=(89,22)

i want to know which point is prior ,index-wise , A or B ? the answer is A , how do i show it in a plot ?

i don't want to create a video of a moving point in time (even though if that's possible in matlab it might be great ) , i think the best option would be a plot of X vs Y with a color changing gradually according to the index of the specific point . is that possible ? are there any other ideas ? would be glad to hear them !