Entirely possible. Neither Metrolinx cocking up by using the same colour twice, nor printing it wrong.
I'd generally assume it was a cock-up on the figure - it always the simplest explanation. Except that they've started using the same, or very similar, colour on the Line 10 signage. I hadn't considered the possibility that they'd have cocked-up twice!
Digging, despite the drawing showing that it comes from the East Harbour Transit Hub Alliance, the detail in the PDF shows it comes from Hatch - who are part of other aspects of the Ontario Line, and not the East Harbour consortium. Which makes sense, but less likely that they'd have goofed, as they'd be in the know. But people don't check things properly these days ...
Personally, I think the SRT Blue would have been a better choice - as long as it wasn't used elsewhere.
Yes, it appears almost identical to the 7 in NYC. And as an aside, NYC operates okay with multiple lines, using the same colour - mostly because of interlining.
Though at times, there's not as much interlining as one would expect.
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