# GLMakie: Create specify point color
**URL:** https://discourse.julialang.org/t/glmakie-create-specify-point-color/131971
**Category:** New to Julia
**Tags:** question, colors, makie, glmakie
**Created:** [August 30, 2025, 4:59pm UTC](https://discourse.julialang.org/t/glmakie-create-specify-point-color/131971 "2025-08-30T16:59:56Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@BananaMaster3](https://discourse.julialang.org/u/BananaMaster3)
#### Post date: [August 30, 2025, 4:59pm UTC](https://discourse.julialang.org/t/glmakie-create-specify-point-color/131971/1 "2025-08-30T16:59:56Z")
I have this code that graphs a scatterplot of points based off their position in the list `points`, then each frame runs a function to update their position and then graphs them again. How can I specify the point’s color when creating it? Here’s the code:
```julia-auto
using GLMakie
po = Observable(Point2f[(0, 0)])
fig, ax = scatter(po)
limits!(ax, 0, 100, 0, 100)
frames = 1:100
for p in points
new_point = Point2f(p.pos.x, p.pos.y)
po[] = push!(po[], new_point)
end
record(fig, "append_animation.mp4", frames, framerate = 20) do frame
global po
update()
i = 1
po[] = []
for p in points
new_point = Point2f(p.pos.x, p.pos.y)
po[] = push!(po[], new_point)
end
end
```
points is a list of a struct I made.
Thank you!
---
### Author:  [@jules](https://discourse.julialang.org/u/jules)
#### Post date: [August 30, 2025, 6:00pm UTC](https://discourse.julialang.org/t/glmakie-create-specify-point-color/131971/2 "2025-08-30T18:00:25Z")
The example on the front page of the docs does this pretty much, use the new `update!` function to change positions and colors at the same time
```julia-auto
points = Point3f[]
colors = Int[]
fig, ax, l = lines(points, color = colors,
colormap = :inferno, transparency = true,
axis = (; type = Axis3, protrusions = (0, 0, 0, 0),
viewmode = :fit, limits = (-30, 30, -30, 30, 0, 50)))
record(fig, "lorenz.mp4", 1:120) do frame
for i in 1:50
push!(points, step!(attractor))
push!(colors, frame)
end
ax.azimuth[] = 1.7pi + 0.3 * sin(2pi * frame / 120)
Makie.update!(l, arg1 = points, color = colors) # Makie 0.24+
l.colorrange = (0, frame)
end
```
---
### Author:  [@BananaMaster3](https://discourse.julialang.org/u/BananaMaster3)
#### Post date: [August 31, 2025, 12:56am UTC](https://discourse.julialang.org/t/glmakie-create-specify-point-color/131971/3 "2025-08-31T00:56:50Z")
I’m very confused by how this function works. Do I give it a point, and a list of RGB values and it will change that point to the color? Or does it take in all the points and all the colors? What format is the color in?
The front page code doesn’t help clear this up. It seems that the colors are a saved memory of previous frame indexes? I can’t find any documentation for this.
---
### Author:  [@jules](https://discourse.julialang.org/u/jules)
#### Post date: [August 31, 2025, 5:19am UTC](https://discourse.julialang.org/t/glmakie-create-specify-point-color/131971/4 "2025-08-31T05:19:21Z")
The update function just updates arbitrary positional and keyword arguments of plots at the same time so they stay in sync. The colors in that example are numbers resolved via a colormap but you can also pass actual colors. An overview is here [Colors | Makie](https://docs.makie.org/stable/explanations/colors#Cheat-Sheet)
---
### Author:  [@eldee](https://discourse.julialang.org/u/eldee)
#### Post date: [August 31, 2025, 8:40am UTC](https://discourse.julialang.org/t/glmakie-create-specify-point-color/131971/5 "2025-08-31T08:40:06Z")
You could still use the `Observable` strategy, if you like:
```julia-auto
using GLMakie, Colors
points = Observable(Point2f[])
colors = Observable(RGB[]) # or Float64[] if you use a colormap
fig, ax, plt = scatter(points, color=colors)
xlims!(ax, 0, 1); ylims!(ax, 0, 1)
display(fig)
for i = 1:100
push!(points[], rand(Point2f))
push!(colors[], rand(RGB))
notify(points); notify(colors) # (Note: we need both notify s)
sleep(0.1)
end
# wait(display(fig)) # if you're running this as a script and don't want the window to close
```
Using
```julia-auto
for i = 1:100
points[] = push!(points[], rand(Point2f)) # notifies here alreay
colors[] = push!(colors[], rand(RGB))
sleep(0.1)
end
```
also seems to work, but this is perhaps\* more dangerous concerning the sync issue @jules mentions: what if the plot already gets updated when `length(points[]) == length(colors[]) + 1`? The manual `update!` in the latest versions of Makie provides a way to avoid this situation.
\*Edit: I’m not sure, but the fact that `scatter` throws an error if you supply differently sized `Vector`s, but nothing happens when you only `push!` to one `Observable`, might indicate that this is sort of already taken care of by just not updating the plot when the lists go out of sync.