Below is a comparison of some emulators i have at hand. I also tried nnnesterj after the screenshot was taken.
SPOILER ALERT - contains a WIP of the background layer use in the ending of Project Blue.
link to screenshot. Both bits R & G are set.
-Mesen is the most accurate. Its presentation is practically exactly the result i'm getting on hardware*, and it seems to me the result is also agreeing with the description on the wiki page.
-While NESST isn't an emulator, i'm happy to have found that it's accurate enough to trust as a previewer.
-nnnesterj is somewhere inbetween fceux and mesen - decent, but not accurate enough to be used as a previewer.
-NDX is more saturated and a bit darker than hardware relative to the normal palette.
-FCEUX seems to behave as if all three bits were set, brightness-wise. (it also defaults xd colours to x0, but that's beside the point).
-Jnes seems to do additive blending, which is what i'd expect from a vs. system or playchoice, but not a famicom/NES
Posting it here in case someone else is looking to use the effect of 2 emphasis bits and need to know what tools/emulators to test it with.
* reference photo of hardware presentation here. It's not completely trustable as it is subject to interpretations made both by the phone camera and the computer screen, but the brightness and saturation is in the ballpark of my ocular observation. Spoiler alert, again. Link.
SPOILER ALERT - contains a WIP of the background layer use in the ending of Project Blue.
link to screenshot. Both bits R & G are set.
-Mesen is the most accurate. Its presentation is practically exactly the result i'm getting on hardware*, and it seems to me the result is also agreeing with the description on the wiki page.
-While NESST isn't an emulator, i'm happy to have found that it's accurate enough to trust as a previewer.
-nnnesterj is somewhere inbetween fceux and mesen - decent, but not accurate enough to be used as a previewer.
-NDX is more saturated and a bit darker than hardware relative to the normal palette.
-FCEUX seems to behave as if all three bits were set, brightness-wise. (it also defaults xd colours to x0, but that's beside the point).
-Jnes seems to do additive blending, which is what i'd expect from a vs. system or playchoice, but not a famicom/NES
Posting it here in case someone else is looking to use the effect of 2 emphasis bits and need to know what tools/emulators to test it with.
* reference photo of hardware presentation here. It's not completely trustable as it is subject to interpretations made both by the phone camera and the computer screen, but the brightness and saturation is in the ballpark of my ocular observation. Spoiler alert, again. Link.