Two LEDs using, probable problem?
Will this setting cause a problem?


No it will not.


  I think if the LED voltage is within the range of the reverse voltage, it's just okay. Is my thought right?


Yes, you are right. As long as you are operating the LEDs within their safe limits, they will not be affected

There are some readily-available, multi-colour bi-directional LEDs on the market. Please follow this link: Led-link