Yes, that's basically it. I think there are at least two different mistakes that can be made.
When a font is rendered you usually calculate the per-pixel coverage. Mistake one is to interpret those coverage values as if they're sRGB colors (so 50% coverage would be #808080 which is a rather dark gray in sRGB, not mid-gray). That makes text look heavier than it should be, and makes diagonal lines look jaggy.
Mistake two is to blend sRGB colors directly rather than converting them to a linear space first. That can give colored fringes on blended images, because the RGB intensities get skewed.
When a font is rendered you usually calculate the per-pixel coverage. Mistake one is to interpret those coverage values as if they're sRGB colors (so 50% coverage would be #808080 which is a rather dark gray in sRGB, not mid-gray). That makes text look heavier than it should be, and makes diagonal lines look jaggy.
Mistake two is to blend sRGB colors directly rather than converting them to a linear space first. That can give colored fringes on blended images, because the RGB intensities get skewed.