fix: match term color (#3694)

site/src/pages/TerminalPage/TerminalPage.tsx

@@ -3,6 +3,7 @@ import { useMachine } from "@xstate/react"
 import { FC, useEffect, useRef, useState } from "react"
 import { Helmet } from "react-helmet-async"
 import { useLocation, useNavigate, useParams } from "react-router-dom"
+import { colors } from "theme/colors"
 import { v4 as uuidv4 } from "uuid"
 import * as XTerm from "xterm"
 import { FitAddon } from "xterm-addon-fit"
@@ -75,9 +76,7 @@ const TerminalPage: FC<
       fontFamily: MONOSPACE_FONT_FAMILY,
       fontSize: 16,
       theme: {
-        // This is a slight off-black.
-        // It's really easy on the eyes!
-        background: "#1F1F1F",
+        background: colors.gray[16],
       },
       rendererType: renderer,
     })