Add multiple colors in axis.text.x names of a ggplot

Question

I have a data frame:

gene_symbol<-c("DADA","SDAASD","SADDSD","SDADD","ASDAD","XCVXCVX","EQWESDA","DASDADS","SDASDASD","DADADASD","sdaadfd","DFSD","SADADDAD","SADDADADA","DADSADSASDWQ","SDADASDAD","ASD","DSADD")
panel<-c("growth","growth","growth","growth","big","big","big","small","small","dfgh","DF","DF","DF","DF","DF","gh","DF","DF")
ASDDA<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDb<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf1<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf2<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf3<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf4<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf5<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDA1<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDb1<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf1<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf11<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf21<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf31<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf41<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf51<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
Gene_states22<-data.frame(gene_symbol,panel,ASDDA,ASDDb,ASDDAf,ASDDAf1,ASDDAf2,ASDDAf3,ASDDAf4,ASDDAf5,ASDDA1,ASDDb1,ASDDAf1,ASDDAf11,ASDDAf21,ASDDAf31,ASDDAf41,ASDDAf51)

and I create a heatmap:

library(ggplot2); library(reshape2)
HG3 <- split(Gene_states22, Gene_states22$panel)
HG4 <- melt(HG3, id.vars= c("gene_symbol","panel"))
HG4 <- HG4[,-5]
HG4$gene_symbol = factor(HG4$gene_symbol, levels = unique(HG4$gene_symbol))

pp <- ggplot(HG4, aes(gene_symbol,variable)) + 
  geom_tile(aes(fill = value),
            colour = "grey50") + 
  scale_fill_manual(values = c("white", "red", "blue", "black", "yellow", "green", "brown")) +
  labs(title = "Heatmap", x = "gene_symbol", y = "sample", fill = "value") +
  guides(fill = FALSE)+
  theme(panel.background = element_rect(fill = NA),
        panel.spacing = unit(0.5, "lines"), ## It was here where you had a 0 for distance between facets. I replaced it by 0.5 .
        strip.placement = "outside",
        axis.text.x = element_text(family = "Calibri", 
                                   size = 11,angle = 45, hjust = 1,color = "red"))


 ggplotly(pp)

I would like to know if it is possible to have multiple colors in axis.text.x names instead of one based either on the panel type they belong or their position (for example first four will be red). Right now they are colored red but I would like to have 6 fifferent colors as many as the panel types. Note that the x.axis.names are placed according to the alphabetical order of the panel they belong.

Answer 1

I added axis.text.x = element_text(family = "Calibri",size = 11,angle = 45,hjust = 1,color = as.factor(panel))). Do you need something like that :

pp <- ggplot(HG4, aes(gene_symbol,variable)) + 
geom_tile(aes(fill = value),
        colour = "grey50") + 
scale_fill_manual(values = c("white", "red", "blue", "black", "yellow", "green", "brown")) +
labs(title = "Heatmap", x = "gene_symbol", y = "sample", fill = "value") +
guides(fill = FALSE)+
theme(panel.background = element_rect(fill = NA),
    panel.spacing = unit(0.5, "lines"), ## It was here where you had a 0 for distance between facets. I replaced it by 0.5 .
    strip.placement = "outside",
    axis.text.x = element_text(family = "Calibri", 
                               size = 11,angle = 45, hjust = 1,color = as.factor(panel)))
pp