diff --git a/R/cell_spec.R b/R/cell_spec.R
index aacac76..d83a8b1 100644
--- a/R/cell_spec.R
+++ b/R/cell_spec.R
@@ -23,13 +23,15 @@
 #' @param angle 0-360, degree that the text will rotate. Can be a vector.
 #' @param hover_message A vector of strings to be displayed as hover message.
 #' Of course, this feature is nly available in HTML.
+#' @param background_as_tile T/F value indicating if you want to have round
+#' cornered tile as background.
 #'
 #' @export
 cell_spec <- function(x, format,
                       bold = F, italic = F, monospace = F,
                       color = NULL, background = NULL,
                       align = NULL, font_size = NULL, angle = NULL,
-                      hover_message = NULL) {
+                      hover_message = NULL, background_as_tile = TRUE) {
 
   if (missing(format) || is.null(format)) format = getOption('knitr.table.format')
   if (is.null(format)) {
@@ -40,7 +42,7 @@
   if (tolower(format) == "html") {
     return(cell_spec_html(x, bold, italic, monospace,
                           color, background, align, font_size, angle,
-                          hover_message))
+                          hover_message, background_as_tile))
   }
   if (tolower(format) == "latex") {
     return(cell_spec_latex(x, bold, italic, monospace,
@@ -50,15 +52,21 @@
 
 cell_spec_html <- function(x, bold, italic, monospace,
                            color, background, align, font_size, angle,
-                           hover_message) {
+                           hover_message, background_as_tile) {
   cell_style <- NULL
   if (bold) cell_style <- paste(cell_style,"font-weight: bold;")
   if (italic) cell_style <- paste(cell_style, "font-style: italic;")
   if (monospace) cell_style <- paste(cell_style, "font-family: monospace;")
-  if (!is.null(color)) cell_style <- paste0(cell_style, "color: ", color, ";")
+  if (!is.null(color)) {
+    cell_style <- paste0(cell_style, "color: ", html_color(color), ";")
+  }
   if (!is.null(background)) {
-    cell_style <- paste0(cell_style, "border-radius: 4px; padding-right: 4px",
-                         ";padding-left: 4px; background-color: ", background, ";")
+    cell_style <- paste0(
+      cell_style,
+      ifelse(background_as_tile, "border-radius: 4px; ", ""),
+      "padding-right: 4px; padding-left: 4px; ",
+      "background-color: ", html_color(background), ";"
+    )
   }
   if (!is.null(align)) {
     cell_style <- paste0(cell_style, "text-align: ", align, ";")
@@ -71,7 +79,9 @@
                          "-webkit-transform: rotate(", angle,
                          "deg); -moz-transform: rotate(", angle,
                          "deg); -ms-transform: rotate(", angle,
-                         "deg); -o-transform: rotate(", angle, "deg);")
+                         "deg); -o-transform: rotate(", angle,
+                         "deg); transform: rotate(", angle,
+                         "deg);")
   }
 
   if (!is.null(hover_message)) {
@@ -96,7 +106,7 @@
   if (!is.null(background)) {
     background <- latex_color(background)
     x <- paste0("\\cellcolor", background, "{", x, "}")
-    }
+  }
   if (!is.null(align)) x <- paste0("\\multicolumn{1}{", align, "}{", x, "}")
   if (!is.null(angle)) x <- paste0("\\rotatebox{", angle, "}{", x, "}")
   return(x)
diff --git a/R/column_spec.R b/R/column_spec.R
index 647f689..a924439 100644
--- a/R/column_spec.R
+++ b/R/column_spec.R
@@ -178,7 +178,7 @@
   }
 
   if (!is.null(color)) {
-    color <- sprintf("\\\\color{%s}", color)
+    color <- paste0("\\\\color", latex_color(color))
   }
 
   if (!is.null(background)) {
diff --git a/R/row_spec.R b/R/row_spec.R
index a6bdb59..ec8a959 100644
--- a/R/row_spec.R
+++ b/R/row_spec.R
@@ -12,8 +12,8 @@
 #' need to be emphasized.
 #' @param monospace A T/F value to control whether the text of the selected column
 #' need to be monospaced (verbatim)
-#' @param color A character string for row text color. Here please pay
-#' attention to the differences in color codes between HTML and LaTeX.
+#' @param color A character string for row text color. For example, "red" or
+#' "#BBBBBB".
 #' @param background A character string for row background color. Here please
 #' pay attention to the differences in color codes between HTML and LaTeX.
 #' @param align A character string for cell alignment. For HTML, possible values could
@@ -132,6 +132,7 @@
                                    "deg); -moz-transform: rotate(", angle,
                                    "deg); -ms-transform: rotate(", angle,
                                    "deg); -o-transform: rotate(", angle,
+                                   "deg); transform: rotate(", angle,
                                    "deg);")
   }
   return(x)
@@ -175,7 +176,7 @@
 
   if (!is.null(color)) {
     new_row <- lapply(new_row, function(x) {
-      paste0("\\\\textcolor{", color, "}{", x, "}")
+      paste0("\\\\textcolor", latex_color(color), "{", x, "}")
     })
   }
 
diff --git a/R/spec_tools.R b/R/spec_tools.R
index 7708118..03b2539 100644
--- a/R/spec_tools.R
+++ b/R/spec_tools.R
@@ -6,13 +6,37 @@
 #' @export
 spec_color <- function(x, alpha = 1, begin = 0, end = 1,
                        direction = 1, option = "D",
-                       na_color = "#BBBBBBFF") {
+                       na_color = "#BBBBBB") {
   x <- round(rescale(x, c(1, 256)))
   color_code <- viridisLite::viridis(256, alpha, begin, end, direction, option)[x]
   color_code[is.na(color_code)] <- na_color
   return(color_code)
 }
 
+html_color_ <- function(color) {
+  if (substr(color, 1, 1) != "#" | nchar(color) != 9) return(color)
+  rgba_code <- col2rgb(color, alpha = TRUE)
+  rgba_code[4] <- round(rgba_code[4] / 255, 2)
+  return(paste0("rgba(", paste(rgba_code, collapse = ", "), ")"))
+}
+
+html_color <- function(colors) {
+  sapply(colors, html_color_)
+}
+
+latex_color_ <- function(color) {
+  if (substr(color, 1, 1) != "#") {
+    return(paste0("{", color, "}"))
+  } else {
+    color <- sub("#", "", color)
+    if (nchar(color) == 8) color <- substr(color, 1, 6)
+    return(paste0("[HTML]{", color, "}"))
+  }
+}
+latex_color <- function(colors) {
+  sapply(colors, latex_color_)
+}
+
 #' Generate common font size for continuous values
 #'
 #' @param x continuous vectors of values
diff --git a/R/util.R b/R/util.R
index f80c89a..27f7d57 100644
--- a/R/util.R
+++ b/R/util.R
@@ -110,13 +110,3 @@
     "\\usepackage{threeparttable}"
   ))
 }
-
-latex_color <- function(color) {
-  if (substr(color, 1, 1) != "#") {
-    return(paste0("{", color, "}"))
-  } else {
-    color <- sub("#", "", color)
-    if (nchar(color) == 8) color <- substr(color, 1, 6)
-    return(paste0("[HTML]{", color, "}"))
-  }
-}