「GROOVY」は FontVibe AI で作成したレインボーの文字エフェクトです。鮮やかな多色レインボーグラデーションの文字エフェクトです。滑らかな色の移り変わり、プリズムのような光、そして陽気で色彩豊かなタイポグラフィが特徴です。

rendered as rainbow text effect — COLOR (mandatory): each individual letter must contain a complete ROYGBIV rainbow gradient top-to-bottom within itself — top=red, upper=orange, mid=yellow-green, lower=blue-indigo, bottom=violet. NOT one color per letter. NOT a gradient across the whole word. Every letter is its own complete rainbow. Full chroma Pride flag saturation — not pastel, not muted, not shifted to any single hue. 'GROOVY' as retro rainbow shadow stacking letters centered at 70% width in square 1:1. Background: vintage 1970s concert venue — warm amber stage lighting from below, crowd bokeh in background, subtle grain texture suggesting aged photography. The retro letterforms with their cascading rainbow shadow layers feel like a classic rock poster come to life on stage. Rich warm atmosphere, festival energy.