I am unable to colour the names of the species in my ggtree. I have consulted with previous questions such as: How to colour the tips of tree by group in ggtree?, but I am unable to apply the solution to my own problem.

Here is my minimal working code:

# Load necessary libraries
library(metacoder)
library(taxize)
library(ggtree)
library(tidyverse)
library(rentrez)

my.db<-data.frame(
  ID=c(1436140, 214434, 426669, 216727, 1223577, 1752675),
  Name=c("Ulnaria acus","Fragilaria pinnata","Ulnaria ulna", "Achnanthes", "Gomphonema clavatum", "Navicula cincta"),
  Blocks=c("Block1","Block2", "Block3", "Block2", "Block3", "Block3"))

class<- classification(my.db$ID, db="ncbi")
class.tree<-class2tree(class, check = TRUE)
tree<-ggtree(tr= class.tree$phylo,
       layout = "fan",
       linewidth=0.15)+
  geom_tree(linewidth=0.15)+
  geom_tiplab(aes(colour=Blocks),
    linewidth = 0,
              size=2.5)
tree

When I run this code, I get the error:

Scale for y is already present.
Adding another scale for y, which will replace the existing scale.
> tree
Error in `label_geom()`:
! Problem while computing aesthetics.
ℹ Error occurred in the 5th layer.
Caused by error:
! object 'Blocks' not found
Run `rlang::last_trace()` to see where the error occurred.

When I specify geom_tiplab(aes(colour=my.db$Blocks), linewidth = 0, size=2.5) in the code, I then get the error:

Error in `label_geom()`:
! Problem while computing aesthetics.
ℹ Error occurred in the 5th layer.
Caused by error in `check_aesthetics()`:
! Aesthetics must be either length 1 or the same as the data (10).
✖ Fix the following mappings: `colour`.
Run `rlang::last_trace()` to see where the error occurred.

Which makes no sense as I only have 6 species in the list grouped in 3 blocks. Why would I need 10 colours?

I ran rlang::last_trace() and got the output:

Backtrace:
     ▆
 1. ├─base (local) `<fn>`(x)
 2. └─ggplot2:::print.ggplot(x)
 3.   ├─ggplot2::ggplot_build(x)
 4.   └─ggplot2:::ggplot_build.ggplot(x)
 5.     └─ggplot2:::by_layer(...)
 6.       ├─rlang::try_fetch(...)
 7.       │ ├─base::tryCatch(...)
 8.       │ │ └─base (local) tryCatchList(expr, classes, parentenv, handlers)
 9.       │ │   └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
 10.       │ │     └─base (local) doTryCatch(return(expr), name, parentenv, handler)
 11.       │ └─base::withCallingHandlers(...)
 12.       └─ggplot2 (local) f(l = layers[[i]], d = data[[i]])
 13.         └─l$compute_aesthetics(d, plot)
 14.           └─ggplot2 (local) compute_aesthetics(..., self = self)
 15.             └─ggplot2:::check_aesthetics(evaled, n)