You typed the name, picked a style you liked, then spent twenty minutes flicking between colour swatches without settling on one. Nothing looked wrong exactly. Nothing looked finished either.
Colour is the part of a name wallpaper people fiddle with longest and think about least. It is also the part that decides whether the thing still reads in a car park at noon, or at six in the morning with the brightness turned right down.
Most of the answer comes from how screens and eyes behave rather than from taste, and once you know that, choosing takes about a minute.
Warm and cool are doing different work
Your eye is not equally sensitive to every colour. Sensitivity peaks in the yellow-green part of the spectrum and drops off at both ends, which is why a pale gold or a mint looks brighter than a deep blue or a deep red shown at the same intensity.
So amber, gold, peach and coral hold their apparent brightness well and survive the screen dimming. Deep blue and violet lose brightness fast, and a navy name on a black background can look almost switched off at low brightness. If you want cool, push it toward cyan, ice blue or teal, which sit nearer the sensitive part of the range.
Saturated blue also focuses differently in the eye than red, so thin blue letters on a dark ground can look soft even when the file is sharp. Thicken the strokes or lighten the blue.
What actually survives sunlight
Outdoors, light lands on the glass and bounces back at you. That reflected light adds to whatever the screen is showing, so blacks turn grey and the difference between two dark shades collapses first.
That explains most outdoor disappointment. A dark outline style, a deep marble, a charcoal name on near-black: all of them look excellent indoors and vanish on a sunny pavement, because the difference you were relying on was between two dark tones. What survives is a wide brightness gap, either bright warm letters on a genuinely dark ground or near-black letters on a pale one.
Screen tinting matters too. True Tone shifts white balance to match the room and Night Shift warms the screen at night, so cool pastels drift toward beige as the day goes on. A slightly more saturated choice holds up either way.
One accent beats three
Three colours fight each other because your eye needs somewhere to land first. If the letters are pink, the glow cyan and the underline gold, nothing is more important than anything else, and the result reads as busy rather than designed.
There is a practical version of the same problem. The lock screen already holds coloured elements you do not fully control: the clock, the date, notification cards, sometimes a widget. Every extra hue is another thing that can clash with those.
The fix is to vary lightness instead of hue. Pick one colour, then build depth from a brighter and a dimmer version of it. A neon name with a halo in the same tone looks richer than one with a contrasting halo, and stays readable because every part tells your eye the same story.
Squint at it before you commit
Set the wallpaper, hold the phone at arm's length and half close your eyes. Squinting throws away fine detail and leaves only brightness differences, which is what your eye uses in the first moment of a glance. If the name still reads as a shape, the colour works. If it dissolves, the problem is contrast, and swapping fonts will not fix it.
Treat the clock as part of the palette
On recent iOS versions you can tint the lock screen clock, and iOS suggests colours pulled from the image. Ignore that and you get a cyan name under a white clock, which is two accents whether you meant it or not.
Two approaches work. Leave the clock white so the name is the only colour on screen, or tint the clock to a quieter version of the name's colour so the two read as one scheme. A clock in a third hue looks unresolved. Clock styles and tint options vary by iOS version and model, so check what your phone offers.
Black backgrounds and the always-on display
Most iPhones since the iPhone X use OLED panels, where black pixels are switched off rather than lit and blocked; the XR and 11 being LCD exceptions. On an OLED phone a mostly black wallpaper really does draw less power than a full-bleed gradient, though the difference across a day is modest next to brightness itself.
It matters more on Pro models from the iPhone 14 Pro onward, which can keep a dimmed lock screen visible. Dimming flatters a dark wallpaper with one bright name and ruins a busy gradient, which turns into a grey smear. If your phone has always-on, check the dimmed version before deciding.
Colours that fall apart when the file is saved
Image files store brightness in full detail but often store colour more coarsely, so a thin, strongly saturated red or blue edge can look fringed after compression while the same shape in white or pale gold stays crisp. Sending the wallpaper to yourself through a chat app compresses it again and makes it worse. Name Wallpaper Maker: Neon saves at full resolution, so save straight to Photos and set it from there.
Quick answers
Which colours work best on a black background?
Anything with real brightness behind it: white, pale gold, ice blue, cyan, coral. They keep a wide gap between letter and background, which is what protects legibility outdoors and at low brightness. Deep blue, burgundy and forest green look rich indoors but lose that gap fast.
Should the name match my case or my icons?
Matching a case works, because you see the two together. Matching icons is harder, since a grid of icons is many colours at once. A wallpaper colour that contrasts with the grid usually looks better than one that blends in.
How many colours is too many?
One accent plus neutrals is the safe answer, and two tones of the same colour still read as a single idea. Once three separate hues compete, the name stops being the subject and the wallpaper starts looking like a sample sheet.
Where to get it
Name Wallpaper Maker: Neon types a name into a finished lock screen in about ten seconds, with styles including neon, gold plate, chrome, retro 3D, aurora, marble and minimal thin, so comparing three colour versions is quicker than imagining them: on the App Store
Make a couple of versions, live with each for a day, and keep the one that still reads well outside.