Nope, checked, double checked, redownloaded, fresh install, unmodded. So maybe you're not remembering/noticed these. All of them occurred in chapter 3.
As mentioned below, I played as a female MC, so I have no idea if this also happens (or not) if playing as a male MC.
Ok, that's what I was thinking, it struck me as odd that this pattern would change.
Playing as a female MC, below the ones where, for me, it didn't turn monochrome
The first occurrence for me was when MC is at the office in Chapter 3, considering if the others where helping or having their own agenda, and decides to call everyone.
Every occurrence afterwards seems related with the options presented here. Whenever the menu with the call options showed, I chose the top one.
In my playthrough that meant not every choice was made by clicking, some of the "Call ..." options seemed to be selected automatically.
So after the choice to "Call Tara" (where there were still 4 options listed), the next time I returned to this menu there were only two left ("Call Rain" and "Call Mara") , where the second one also got automatically selected after ending Rain's call.
- At MC's workplace, ch003a.rpy, label ch003slot1, the jump at line 290 to ch003stories.rpy, label ch003storychoice . First option listed "Call Sophia"
- Aiden's basement, ch003a.rpy, label ch003sophia, the choice menu starting at line 416
- Back at MC's workplace, ch003a.rpy, label ch003slot3, the jump at line 300 to ch003stories.rpy, label ch003storychoice. First option listed "Call Tara"
- MC's home, B visiting, ch003sexscenes.rpy, label ch003bflirtcheck, the choice menu starting at line 75
- MC's home, B joined by Sophia, ch003sexscenes.rpy, label ch003bflirtcheck, the choice menu starting at line 375
- MC's home, B joined by Sophia, ch003sexscenes.rpy, label ch003bflirtcheck2, the choice menu starting at line 526
- MC's home, Just B, ch003sexscenes.rpy, label ch003bflirtcheck2, the choice menu starting at line 584
- MC's home, Just B, ch003sexscenes.rpy, label ch003bflirtcheck2, the choice menu starting at line 621
- MC's home, Just B, ch003sexscenes.rpy, label ch003bflirtcheck2, the choice menu starting at line 677
- Back at MC's workplace, ch003a.rpy, label ch003slot4, the jump at line 310 to ch003stories.rpy, label ch003storychoice. First option listed "Call Rain"
- Mara talking to Sylvia, ch003stories.rpy, label ch003mara, the choice menu starting at line 1032
- Mara talking to Sylvia, ch003stories.rpy, label ch003mara, the choice menu starting at line 1156
- Mara visiting MC, ch003sexscenes.rpy, label ch003marasexscenef, the choice menu starting at line 1465
These were the ones where it happened in my playthrough.
And of course the corkboard, technically there's no menu showing, but since you still need to make choices here which character to review, it felt odd to not have it show monochrome and only the hovered photo in color with the board only showing in full color after a photo was clicked. Some experimenting showed it would actually work. To not have to repeat the monochrome call at the end of every review, instead of having it shown just before the end of label ch003finale, it would only need to be shown at the start of label ch003board before the
screen ch003mythosboard():
statement. so every time you return here after a review it would show monochrome again and only the hovered photo in color with the board only showing full color after having clicked a photo.