How can I change cursor color in VSCode?

Try adding this to your global preferences file:

"workbench.colorCustomizations": {
    "editorCursor.foreground": "#ffff00",
    "terminalCursor.foreground": "#ffff00"
}

Also worth noting that if you’re colourblind, there are probably some colourblind-friendly themes for vscode out there, though I can’t say I have looked for them myself.