In the preferences, default file settings you get this instruction for changing the width and color of indent guides.
// Set to false to turn off the indentation guides.
// The color and width of the indent guides may be customized by editing
// the corresponding .tmTheme file, and specifying the colors "guide",
// "activeGuide" and "stackGuide"
"draw_indent_guides": true,
I’m using the sofa theme and opened it. What should I add and where to increase the width of the guides. I find the 1 pixel dotted line a bit hard to see. I managed to change the color by adding
<key>guide</key>
<string>#000000</string>
to my Espresso Soda.tmTheme file at the top.