Molex to 5mm LEDs safe?

[mcgge1360]

My case has 2 5mm LEDs in parallel as a power light. Instead of plugging into the header, it uses molex. (5v and ground, I believe) there are no resistors, it just goes straight to the LEDs. From Arduino I thought these LEDs couldn't handle 5v, and required a 220 or higher ohm resistor, but these have none (and work fine). Is it safe to wire new LEDs to the spots that the other LEDs are? I'm trying to make my case all red instead of blue.

Thanks!

 

[grimfox]

It is not a good idea to run LEDs without a resistor. Their internal resistance is not sufficient in most cases to prevent a high current draw that would burn them out.

About the only time it is safe to run an LED without a resistor is when the power supply is capable of automatically regulating the current (most power supplies are not capable of doing this) or the internal resistance is high enough as is the case in some coin cell battery applications.