is there a way (analogue to FontLab’s metrics window) to see letters side by side while elaborating curves on a glyph?
If it is the “Text Preview” (maybe there is another method I cannot find) is there a way to change the letters color from black? Not that I am a fan of colors on letters but, personally, I do not like the brutal black on white specially if the font is viewed on larger size. I need grey tones.
A separate window is not necessary to view letters side by side.
You can type words in the Edit view with the Text tool (shortcut T). Hold down the space bar while editing a glyph to temporarily switch to a pure rendering. You can also type a letter twice, so you can see a rendering and the editing right next to each other.
Again, there is no need for a separate window to achieve this. You can set a canvas color in Glyphs > Preferences > Appearance, and you can set a Master Color in File > Font Info > Masters > Custom Parameters: