Orps eggs should never be blue. Lavender Ameraucanas were breed to Orps to crete the Lav. Orp color. Blue eggs can show up in the first couple of generations. They may also have rose combs and beards and muffs. The blue egg color, rose comb and the muffs should be bred out of a Lav. Orp project.
If the breeder you got them from started their own project then that may be why the eggs are still blue. If your birds have straight combs they will most likely lay brown eggs, but it is not guaranteed. If you are working on a lav project, I would not hatch the blue eggs from this generation.
How long have you owned your birds? I would be surprised if they are really 8 months as their bodies are still fairly slender and their combs are more pink than red. Based on comb color I'd say they have at least 1month to go before laying.