Ayu Islands v2.5 — a JetBrains theme engine with per-project accent propagation, Kotlin-specific syntax tokens, and workspace auto-fit
I've been building Ayu Islands — a theme plugin for IntelliJ-based IDEs that started as an Ayu Mirage port and turned into something closer to an IDE customization engine. Built with Kotlin + IntelliJ Platform SDK, currently at v2.5.3.
A few things that might be interesting from a technical standpoint:
Kotlin & Java syntax depth: Kotlin has 31 dedicated tokens: mutable variables get underlines, smart casts get a background tint, named arguments have their own color, labels like forEach are visually distinct from keywords, and annotations (both regular and built-in) have dedicated styling separate from other metadata. Java has 45 tokens with similar granularity. Injected language fragments and TODO/FIXME patterns have their own styling too.
Per-project & per-language accent propagation — you pin a color to a project path or a programming language. The plugin reads your project's file breakdown (e.g. "Kotlin 95% · Java 3% · other 2%") and applies the matching pin. Priority chain: project override → language override → global accent. The color propagates through the entire UI pipeline — not just the title bar like IntelliJ's built-in 2023.2 project accent. Scrollbars, caret line, search highlights, bracket matches, glow borders, and third-party plugins (CodeGlance Pro, Indent Rainbow) all follow.
Glow engine — neon glow borders on Islands UI panels. Rendered as layered overlay with three styles (Soft, Sharp Neon, Gradient), three animation modes (Pulse, Breathe, Reactive), and seven panel targets. Syncs with the active accent color including project overrides.
Workspace auto-fit — Project View, Commit panel, and Git panel auto-resize with configurable min/max pixel bounds. Git panel internal splitter controls the branches tree vs. file changes tree ratio. You can also hide editor scrollbars and the Project View filesystem path.
In-IDE font management — four curated coding font presets (Victor Mono, Maple Mono, Monaspace Neon, Monaspace Xenon) with one-click download, live preview, size/weight/ligature controls, and consent dialog with exact install path. Delete reverts to JetBrains Mono.
Free tier is the complete theme — 6 variants (Mirage/Dark/Light × Classic/Islands UI), all syntax highlighting, accent presets, font presets. Premium adds the customization engine on top. 30-day trial unlocks everything on install, no credit card.