diff --git a/rpcsx-os/iodev/stderr.cpp b/rpcsx-os/iodev/stderr.cpp
index 808d62f88..639548685 100644
--- a/rpcsx-os/iodev/stderr.cpp
+++ b/rpcsx-os/iodev/stderr.cpp
@@ -11,10 +11,11 @@ struct StderrDevice : public IoDevice {
 static std::int64_t stderr_instance_write(IoDeviceInstance *instance,
                                           const void *data,
                                           std::uint64_t size) {
-  if (size)
+  static const bool istty = isatty(fileno(stderr));
+  if (size && istty)
     std::fprintf(stderr, "\e[0;35m");
   auto result = std::fwrite(data, 1, size, stderr);
-  if (size)
+  if (size && istty)
     std::fprintf(stderr, "\e[0m");
   std::fflush(stderr);
 
diff --git a/rpcsx-os/iodev/stdout.cpp b/rpcsx-os/iodev/stdout.cpp
index 960f7b4d0..338f45736 100644
--- a/rpcsx-os/iodev/stdout.cpp
+++ b/rpcsx-os/iodev/stdout.cpp
@@ -11,10 +11,11 @@ struct StdoutDevice : public IoDevice {
 static std::int64_t stdout_instance_write(IoDeviceInstance *instance,
                                           const void *data,
                                           std::uint64_t size) {
-  if (size)
+  static const bool istty = isatty(fileno(stdout));
+  if (size && istty)
     std::fprintf(stdout, "\e[30;1m");
   auto result = std::fwrite(data, 1, size, stdout);
-  if (size)
+  if (size && istty)
     std::fprintf(stdout, "\e[0m");
   std::fflush(stdout);