Help with lighting up a butt load of diodes

Im doing a big 3D-model of my school and need to control about 200 diodes with 1 arduino (the diodes are gonna light up the way to a chosen classroom). I don't know how to contol that many and need advice. I would like to have some kind of blinking feature on every diode. What can I use? How should i think when I make the circuit?

The simplest answer to implement will probably be neopixels. BUT.... theres a cost associated and they can use a fair chunk of power (depending on how bright you set them).

The adafruit site has some nice info on them if you want to go read.

ghostiisan:
Im doing a big 3D-model of my school and need to control about 200 diodes with 1 arduino (the diodes are gonna light up the way to a chosen classroom). I don't know how to contol that many and need advice. I would like to have some kind of blinking feature on every diode. What can I use? How should i think when I make the circuit?

You could use "WS2812" Neopixel RGB-LEDs as hardware.
It will just need one data pin on your Arduino to control all 200 LEDs in RGB colors (each of them seperately).

There are at least two libraries you can use, I think one of them is named Neopixel library and the other one FastLed library.

A good power source is needed as well. Neopixel LEDs tontrolled to "full bright white RGB255,255,255) will draw up to 20mA for each color channel, that's 320mA = 60mA total per LED.
200 WS2812 LEDs at brightest white may draw 200
60mA = 12000mA = 12 amperes total @5V.

So you need a 5V power source which can deliver 12 amperes or more.

And you cannot feed 12 amps into one end of the LED strand to feed all 200 LEDs from one end of the chain, but you have to feed power into the LED strand after every 50 LEDs (at most).