diff --git a/R-package/NAMESPACE b/R-package/NAMESPACE
index 3a590f27a..a9ae672a3 100644
--- a/R-package/NAMESPACE
+++ b/R-package/NAMESPACE
@@ -37,6 +37,7 @@ importFrom(data.table,setnames)
 importFrom(magrittr,"%>%")
 importFrom(magrittr,add)
 importFrom(magrittr,not)
+importFrom(stringr,str_detect)
 importFrom(stringr,str_extract)
 importFrom(stringr,str_extract_all)
 importFrom(stringr,str_match)
diff --git a/R-package/R/xgb.model.dt.tree.R b/R-package/R/xgb.model.dt.tree.R
index 5833389e2..13d3ecc5b 100644
--- a/R-package/R/xgb.model.dt.tree.R
+++ b/R-package/R/xgb.model.dt.tree.R
@@ -12,7 +12,6 @@
 #' @importFrom magrittr add
 #' @importFrom stringr str_extract
 #' @importFrom stringr str_split
-#' @importFrom stringr str_extract
 #' @importFrom stringr str_trim
 #' @param feature_names names of each feature as a character vector. Can be extracted from a sparse matrix (see example). If model dump already contains feature names, this argument should be \code{NULL}.
 #' @param filename_dump the path to the text file storing the model. Model dump must include the gain per feature and per tree (parameter \code{with.stats = T} in function \code{xgb.dump}).
diff --git a/R-package/R/xgb.plot.multi.trees.R b/R-package/R/xgb.plot.multi.trees.R
index d30d86332..f53d1a13f 100644
--- a/R-package/R/xgb.plot.multi.trees.R
+++ b/R-package/R/xgb.plot.multi.trees.R
@@ -7,6 +7,8 @@
 #' @importFrom data.table setnames
 #' @importFrom data.table :=
 #' @importFrom magrittr %>%
+#' @importFrom stringr str_detect
+#' @importFrom stringr str_extract
 #' 
 #' @param filename_dump the path to the text file storing the model. Model dump must include the gain per feature and per tree (parameter \code{with.stats = T} in function \code{xgb.dump}).
 #' @param model dump generated by the \code{xgb.train} function. Avoid the creation of a dump file.
@@ -83,9 +85,8 @@ xgb.plot.multi.trees <- function(model, names, features.keep = 5, plot.width = N
                                     label = nodes.dt[,Text],
                                     style = "filled",
                                     color = "DimGray",
-                                    fillcolor= "Blue",
-                                    shape = "oval", 
-                                    #data = allTrees[,Feature]
+                                    fillcolor= "Beige",
+                                    shape = "oval",
                                     fontname = "Helvetica"
   )