Rainbow text animation using only CSS

Question

I got inspired by this Rainbow Text Animation rainbow-text-animation, and I would like to use only CSS to make this happen instead of all that complicated SCSS coding.

I got what I like so far and now I just want to make it go from left to right AND having multiple colors in one entire line instead of one color at a time.

Run the code snippet to see what I'm talking about.

So as you can see, I want as many colors I want in one line and not one color in the entire line (one at a time).

#shadowBox {
  background-color: rgb(0, 0, 0);
  /* Fallback color */
  background-color: rgba(0, 0, 0, 0.2);
  /* Black w/opacity/see-through */
  border: 3px solid;
}

.rainbow {
  text-align: center;
  text-decoration: underline;
  font-size: 32px;
  font-family: monospace;
  letter-spacing: 5px;
  animation: colorRotate 6s linear 0s infinite;
}

@keyframes colorRotate {
  from {
    color: #6666ff;
  }
  10% {
    color: #0099ff;
  }
  50% {
    color: #00ff00;
  }
  75% {
    color: #ff3399;
  }
  100% {
    color: #6666ff;
  }
}

<div id="shadowBox">

  <h3 class="rainbow">COMING SOON</h3>

</div>

Macintosh

Answer 1

You can achieve this effect by using a moving gradient background, color to transparent, and background clip to text.

#shadowBox {
    background-color: rgb(0, 0, 0);
    /* Fallback color */
    background-color: rgba(0, 0, 0, 0.2);
    /* Black w/opacity/see-through */
    border: 3px solid;
}

.rainbow {
    text-align: center;
    text-decoration: underline;
    font-size: 32px;
    font-family: monospace;
    letter-spacing: 5px;
}
.rainbow_text_animated {
    background: linear-gradient(to right, #6666ff, #0099ff , #00ff00, #ff3399, #6666ff);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    animation: rainbow_animation 6s ease-in-out infinite;
    background-size: 400% 100%;
}

@keyframes rainbow_animation {
    0%,100% {
        background-position: 0 0;
    }

    50% {
        background-position: 100% 0;
    }
}

<div id="shadowBox">
    <h3 class="rainbow rainbow_text_animated">COMING SOON</h3>
</div>

Repetition

Sweet that worked, so now how can I change this to go from left to right instead of right to left and change the speed? – Macintosh

You can freely change the speed by adjusting the duration of the .rainbow_text_animated animation. (Say changing 6s to 12s to double the slowness) At the moment it is moving the gradient background to the right, then to the left, then back to the right etc. This creates the "loop" effect. – Repetition

Oh sweet man! Thanks for the clarification! And thanks for your help! Just what I needed to make my life much more simpler. SCSS is still out of my league. I got the book to learn Responsive Design using SASS but I rather start by learning media queries to make understanding responsive design a lot easier before advancing. – Macintosh

Tip: Put speed at 1s for a cooler effect! – Cuellar

I ran into an issue with this on my web core vitals, it gets flagged on the LCP metric as the animation is not composited. web.dev/articles/…. Is anyone able to help in creating this animation using transforms instead? – Spoilsport

Answer 2

#shadowBox {
  background-color: rgb(0, 0, 0);
  /* Fallback color */
  background-color: rgba(0, 0, 0, 0.2);
  /* Black w/opacity/see-through */
  border: 3px solid;
}

.rainbow {
  text-align: center;
  text-decoration: underline;
  font-size: 32px;
  font-family: monospace;
  letter-spacing: 5px;
  animation: colorRotate .5s linear 0s infinite;
}

@keyframes colorRotate {
  from {
    color: #6666ff;
  }
  10% {
    color: #0099ff;
  }
  50% {
    color: #00ff00;
  }
  75% {
    color: #ff3399;
  }
  100% {
    color: #6666ff;
  }
}

<div id="shadowBox">

  <h3 class="rainbow">VERB</h3>

</div>

Huntlee

Please don't post only code as answer, but also provide an explanation what your code does and how it solves the problem of the question. Answers with an explanation are usually more helpful and of better quality, and are more likely to attract upvotes. – Transeunt

This does not solve the OP's question. The OP is asking how to have multiple colours present at the same time, not cycling through the colours one at a time. – Repetition

Answer 3

#shadowBox {
    background-color: rgb(0, 0, 0);
    /* Fallback color */
    background-color: rgba(0, 0, 0, 0.2);
    /* Black w/opacity/see-through */
    border: 3px solid;
}

.rainbow {
    text-align: center;
    text-decoration: underline;
    font-size: 32px;
    font-family: monospace;
    letter-spacing: 5px;
}
.rainbow_text_animated {
    background: linear-gradient(to right, #6666ff, #0099ff , #00ff00, #ff3399, #6666ff);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    animation: rainbow_animation 6s ease-in-out infinite;
    background-size: 400% 100%;
}

@keyframes rainbow_animation {
    0%,100% {
        background-position: 0 0;
    }

    50% {
        background-position: 100% 0;
    }
}

<div id="shadowBox">
    <h3 class="rainbow rainbow_text_animated">COMING SOON</h3>
</div>

Rysler

The code in this code-only answer is copied verbatim from this answer to this question by Austen Holland without attribution. – Diggs