颜色的ggplot图例显示点而不是条形

Question

documentFracation <- c(0.164, 0.196, 0.102, 0.166, 0.145, 0.017, 
                       0.144, 0.258, 0.139, 0.019, 0.155, 0.013,
                       0.001,0.099,0.007)

tsSTDCommoncrawl <- c(19,21,23,30,33,34,
                      38,52,54,65,90,123,
                      180,181,1014)

average_dice <- c(0.495, 0.505, 0.495, 0.615, 0.48, 0.385, 
                  0.5, 0.555, 0.4, 0.33, 0.405, 0.33, 
                  0.19, 0.32, 0.145)

std_dice <- c(0.278, 0.213, 0.240, 0.184, 0.175, 
              0.240, 0.282, 0.261, 0.262, 0.2188, 
              0.2191, 0.1989, 0.143, 0.1874, 0.086)

data2 <- data.frame(type=crawls, df=documentFracation, ts=tsSTDCommoncrawl,
                    avgdice=average_dice)


# generate scatter plot chart by crawl type with size of point corresponding to max dice value
p <- ggplot() +
  geom_point(data=data2, aes(x=df, y=ts, size=avgdice, fill = std_dice), shape=21)

p <- p + scale_y_continuous(trans = 'log10')

# add labels besides points
p <- p + geom_text(data=data2, aes(x=df, y=ts, label=avgdice), size=2, hjust=0.5,vjust= -2)

#add scaled colr as paired color from brewer
#p <- p + scale_color_manual(values=colors)

# legend title
p <- p + guides(fill =
                  guide_legend(title = "",
                               label.position = "right",
                               #keywidth=0.25,
                               #keyheight=0.2,
                               default.unit="inch")) + theme(legend.position="right")

p <- p + xlab("document fraction between commoncrawl and directcrawl") + 
  ylab("timestamp interval standard deviation in commoncrawl (log10 scale)") + 
  ggtitle("Average Dice value with document fraction \nand timestamp inverval variation") +
  #mar=c(top,right,bottom,left)
  theme(plot.margin = unit(c(1,1,1,1),"cm"))+
  theme(plot.title = element_text(hjust = 0.5))

print(p)

我使用上面的代码，我生成的图表看起来像

在图的右侧，为什么颜色代码图例是点而不是条？为什么我有“avgdice”的传说而不是颜色（我使用std_dice来填充颜色）？我希望颜色图例如下所示：

感谢您的帮助！