Union const colors

[GuillaumeGomez]

Fixes #43523

What do you think of these colors:

?

[rust-highfive]

Some changes occurred in HTML/CSS.

cc @GuillaumeGomez

[rust-highfive]

r? @arielb1

(rust_highfive has picked a reviewer for you, use r? to override)

[GuillaumeGomez]

cc @rust-lang/docs

[QuietMisdreavus]

The "Union" could stand to be a bit darker, but it also feels about as light as the primitive color, so i'll let it fly.

@TedDriggs - you wanted to check out the new colors, this is the PR that adds them.

[carols10cents]

Red/green colorblindness is the most common kind, so structs and enums might not be distinguishable from each other. I have a friend who has some colorblindness, would you like me to run this by him?

[GuillaumeGomez]

@carols10cents: It'd be very helpful! Maybe he can suggests better colors as well? :)

[carols10cents]

Maybe he can suggests better colors as well? :)

It's quite likely! Asking!

[carols10cents]

Ok! I sent my friend the screenshot and this is what he has to say:

Struct & Trait are visually distinct. CONST and Union are hard to discern for me as text colors. Enum is fine compared to Struct and Trait, but gets a little lost to me next to Union or CONST.

Is this syntax highlighting for the documentation? If so, I'd recommend stronger contrast all around if they're meant to sit on a light background.

Neither CONST nor Union pass WCAG contrast guidelines for use against a white background (http://leaverou.github.io/contrast-ratio/#rgb%28200%2C153%2C89%29-on-white and http://leaverou.github.io/contrast-ratio/#rgb%28193%2C200%2C59-on-white).

Enum is cutting it close too (http://leaverou.github.io/contrast-ratio/#rgb%28105%2C148%2C94%29-on-white). Upping contrast definitely helps me distinguish colors.

I hope this helps. I'll load the colors into the contrast ratio tool and mess around with them to see if I can come up with something I think looks good and is easily distinguishable for me at small sizes against white. :)

[arielb1]

r? @QuietMisdreavus (or someone else on the docs team)

[jnf]

Hello! I'm the friend @carols10cents referenced above. I have (relatively mild) colorblindness, primarily in distinguishing warm tones. I put together a Code Pen with some contrast comparisons and an alternate palette. I don't have any context for how these colors are used (my guess is syntax highlighting for docs), so please forgive any misuse.

Anyway, thank you Carol for asking. Yinz keep being this awesome and considerate and I may just have to learn some Rust. ^_^

[GuillaumeGomez]

I'll take a look and try to make it easier for colorblind people to see the difference.

[kennytm]

The complete list of colors, as the Code Pen only listed five. CR=4.5-ing done via http://accessible-colors.com/. Just raising the contrast should not be enough, if the CR of every color is 4.5 they would all become the same shade of gray when the hue is washed out.

Kind	Original color	After CR=4.5'ed
Struct
Typedef
Const (this PR)
Function
Union (this PR)
Enum
Macro
Primitive
Module
Trait

(Coblis simulation of above)

[GuillaumeGomez]

Here is the new output:

Is it fine or is there something else I can do?

[steveklabnik]

As long as the contrast is high enough, I'm 👍

[QuietMisdreavus]

Looks good to me! I'd like to hear from the others in this thread first, though.

[carols10cents]

I defer entirely to @jnf (who has a non-Rust real job in PST so will likely comment in a few hours at the earliest, thank you again for your time on this Jeremy!!!)

[kennytm]

@GuillaumeGomez Could we keep functions brown and assign the blue to constants or unions? Existing colors should better be kept "stable".

[GuillaumeGomez]

Ok, switched functions and constants color:

[ollie27]

What about statics? There are also structfield, variant, associatedtype and associatedconstant.

For all of these the background highlight color on the search page will also need to be updated to match:

rust/src/librustdoc/html/static/styles/main.css

Lines 73 to 80 in b0424b5

	.content .highlighted.trait { background-color: #fece7e; }
	.content .highlighted.mod { background-color: #afc6e4; }
	.content .highlighted.enum { background-color: #b4d1b9; }
	.content .highlighted.struct { background-color: #e7b1a0; }
	.content .highlighted.fn { background-color: #c6afb3; }
	.content .highlighted.method { background-color: #c6afb3; }
	.content .highlighted.tymethod { background-color: #c6afb3; }
	.content .highlighted.type { background-color: #c6afb3; }

.

[GuillaumeGomez]

@ollie27: Forgot about them. I update as soon as I can!

[GuillaumeGomez]

Updated!

[GuillaumeGomez]

Anything else to do in here?

[ollie27]

Any reason not to add colors for statics? After this they'll be the only item type that gets a full page but no colors.

The background highlight colors for trait and type are still wrong but I guess that's a pre-existing bug. There are still no background colors for macro, constant, primitive, externcrate and static.

[GuillaumeGomez]

@ollie27: Fixed as well! Anything else?

[ollie27]

Looks good to me 👍

[GuillaumeGomez]

Since you were the last one having issues, I suppose we can r+?

[QuietMisdreavus]

It sounds like any interested party is okay with what's left, or was willing to defer to someone else. Let's get this out the door. If anyone finds any more issues with contrast, open another issue and we can work it out!

@bors r+ rollup

[bors]

📌 Commit 00b362e has been approved by QuietMisdreavus

[bors]

⌛ Testing commit 00b362e with merge 0188ec6...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: QuietMisdreavus
Pushing 0188ec6 to master...