Loosen up blob blue delta threshold

Seems like there can be a good amount of glare when closer to the
target, even at night.

Signed-off-by: Milind Upadhyay <milind.upadhyay@gmail.com>
Change-Id: I67fd9f18893ae2e486407c218a9dbb8d4d67276f
diff --git a/y2022/vision/blob_detector.cc b/y2022/vision/blob_detector.cc
index 2d5ae63..7bbd1f3 100644
--- a/y2022/vision/blob_detector.cc
+++ b/y2022/vision/blob_detector.cc
@@ -13,7 +13,7 @@
 
 DEFINE_uint64(red_delta, 100,
               "Required difference between green pixels vs. red");
-DEFINE_uint64(blue_delta, 50,
+DEFINE_uint64(blue_delta, 30,
               "Required difference between green pixels vs. blue");
 
 DEFINE_bool(use_outdoors, false,