Here’s the simplest way to make a custom red liner in Roblox: use Roblox Studio, pick the object you want to recolor, and change its color/material to a red shade that fits your design. Roblox’s creator docs note that materials control an object’s visual appearance, and custom textures/colors can be added in Studio as part of your build.

Quick Scoop

If by “red liner” you mean a red accent line, border, or trim effect, the usual method is:

  1. Open your place in Roblox Studio.
  2. Insert or select the part/UI element you want to style.
  3. Set the color to red and adjust the shade.
  4. Add a thin part, frame, or texture to create the “liner” look.
  5. Test it in Play mode to make sure the thickness and placement look right.

For GUI, a dark red like #BE1E1E can work well for sharp outlines or warning-style accents, while brighter reds are better for highlights.

For game assets

If you want the red liner on a 3D object, use a thin Part or MeshPart and position it along the edge of the surface. You can also use materials and textures to make it look cleaner or more stylized, since Roblox materials affect both appearance and physical feel. The Creator Hub also documents custom colors and textures for parts, which is the standard route for this kind of effect.

For UI

If you meant a red liner in a menu, health bar, or overlay, use a Frame with a red BackgroundColor3, then shrink its height or width to create a line. The Oreate AI example suggests red UI accents often need some opacity tuning so they don’t clash with dark backgrounds.

About REDLINER

If you actually meant the Roblox game REDLINER , then it is a movement- and-combat game centered on dash, slide, wallrun, parry, and attack mechanics rather than an editing feature. A recent guide says the core controls involve shifting to dash, sliding with control while moving, and using timing-based combat actions.

Best approach

  • Use Studio for the actual customization.
  • Use a thin part for a 3D red trim.
  • Use a Frame for UI lines.
  • Pick a red tone that matches the rest of the design.
  • Test in-game so the liner does not look too thick or too bright.

If you meant a specific “red liner” style from a video or a Roblox avatar effect, the exact steps depend on whether it’s for a map, a UI, or a character outfit.