# How to make colors faint/transparent when plotting a color plane using Plots?

**URL:** <https://discourse.julialang.org/t/how-to-make-colors-faint-transparent-when-plotting-a-color-plane-using-plots/83017>\
**Category:** Visualization\
**Tags:** colors, plots\
**Created:** [June 19, 2022, 2:16pm UTC](https://discourse.julialang.org/t/how-to-make-colors-faint-transparent-when-plotting-a-color-plane-using-plots/83017 "2022-06-19T14:16:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Torkel](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/torkel/32/5030_2.png) [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Post date:** [June 19, 2022, 2:16pm UTC](https://discourse.julialang.org/t/how-to-make-colors-faint-transparent-when-plotting-a-color-plane-using-plots/83017/1 "2022-06-19T14:16:04Z")

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Hello,  
I want to plot a colour plane using plots, e.g.

```julia
using Plots
plot([RGB{Float64}(0.0,0.0,1.0) RGB{Float64}(1.0,0.0,0.0); RGB{Float64}(1.0,0.0,0.0) RGB{Float64}(1.0,0.0,0.0)])

```

![image](https://global.discourse-cdn.com/julialang/original/3X/0/3/0337f563655b216802546fc918401df3462042c6.png)

Is there a way to make this faint/transparent (I then want to plot stuff above, so would be better if this was fainter). I have tried various `alpha`, `markeralpha`, `linealpha`, `fillalpha` without success.

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<div class="post-metadata">

**Author:** ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Post date:** [June 19, 2022, 9:12pm UTC](https://discourse.julialang.org/t/how-to-make-colors-faint-transparent-when-plotting-a-color-plane-using-plots/83017/2 "2022-06-19T21:12:12Z")

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You can use RGBA and set alpha as last parameter:

```julia
plot([RGBA{Float64}(0.0,0.0,1.0,0.5) RGBA{Float64}(1.0,0.0,0.0,0.5); RGBA{Float64}(1.0,0.0,0.0,0.5) RGBA{Float64}(1.0,0.0,0.0,0.5)])

```

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<div class="post-metadata">

**Author:** ![Torkel](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/torkel/32/5030_2.png) [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Post date:** [June 20, 2022, 8:08am UTC](https://discourse.julialang.org/t/how-to-make-colors-faint-transparent-when-plotting-a-color-plane-using-plots/83017/3 "2022-06-20T08:08:25Z")

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Thanks!